I was wearing a teal Tomas Hertl shirsey the morning I went into labor with my firstborn son. This was a conscious choice. It was Thanksgiving of 2015, and a few weeks earlier the long-haired hippie lady who led my birthing class had urged us to surround ourselves with cherished objects during our deliveries so as to maximize the good vibes all around.

I had gone home, overthought it, and finally added a few items to my go bag: a tiny but ornate matryoshka doll from St. Petersburg that reminded me of the wonder of discovery; a crystal votive holder that cast twinkling light on the walls like the sun hitting the ocean floor; and my Hertl shirsey, which in addition to being really soft also commemorated the thrill of new beginnings, having been purchased two years before as a souvenir of the unforgettable night I saw a joyous Czech teen score four goals in his third NHL game.

On October 8, 2013, I had gone to SAP Center in San Jose because the New York Rangers were in town, and I thought maybe I’d try to interview goalie Henrik Lundqvist or something. Instead, Lundqvist was pulled halfway through the game when Hertl scored on him to give the Sharks a 4-0 lead, and then the rookie went on to merrily add three more goals after that, the last of which featured such sharp angles and such audaciousness that it made him look like a pixelated arcade hockey player come to life.

After the game, he kinda sounded like one, too. “This is dream,” he said, between the widest of smiles. “No reality. I’m happy and crazy and I don’t know and big game and this is dream.”

It was precisely this aura that I was hoping for, and that I ultimately got, in the delivery room two years later—earnest and babbling and exhausted and thrilled, just like Hertl himself.

Hertl is no longer a rookie, but he still plays with the giddy gallop of one. This season was his most productive yet: He scored 35 goals and added 39 assists in 77 games, far exceeding his previous career highs. And in the first two rounds of the playoffs, his performance has reached another level: Hertl has 14 points in 14 playoff games this spring, helping the Sharks advance to the Western Conference final against the St. Louis Blues for the second time in four years. His postseason contributions have included six multipoint games, a shorthanded double-OT winner, and a goal and an assist during an epic (if controversial) four-goal Sharks power play in Game 7 of the first round. He is one of the top contenders for the Conn Smythe, awarded to the playoffs’ MVP.

Six seasons after Hertl made an NHL splash so delightful that it somehow became part of my first childbirth, the guy once known as Teenage Mutant Ninja Hertl is still playing like he’s Robert Plant asking “does anybody remember laughter?” on skates. His enthusiasm is infectious and his impishness is elite; reporters who interview him find it hard to keep a straight face. But don’t take that to mean he isn’t a serious threat. If Hertl can maintain the caliber of play he has demonstrated all season, there could be plenty of laughter in San Jose before too long, and a whole lot of people wandering around feeling the way he so often has: all happy and crazy and I don’t know and big game and this is dream.

Before arriving in the U.S., Hertl participated in a hilarious photo shoot meant to mimic a famous advertisement featuring his larger-than-life Czech countryman, Jaromir Jagr. And during his rookie season, speaking with the San Jose Mercury-News, Hertl compared himself to the future Hall of Famer in a very matter-of-fact way. “Both of us have big bottoms,” he said, “and I just try to use my big bottom as Jagr does.”

With that big Czech ass and those dazzling goals, Hertl established himself as a significant factor for the Sharks almost immediately upon his debut in 2013. What he lacked in the category of “graceful skating” he made up for just about everywhere else: He could be tricksy without being soft, he could play defense without sacrificing his assertive offensive production, and despite being big and not necessarily speedy, he was agile. And his arrival to the team came at a crucial juncture for a franchise in transition, helping to prop open a championship window that felt like it was beginning to slam shut. Hertl played a part of the franchise’s Patrick Marleau–Joe Thornton–driven past, and his role is only expected to grow as the franchise navigates the upcoming free-agency market and considers its wide-open future.

But it’s Hertl’s off-ice demeanor that has really endeared him to fans and casual onlookers alike. In his rookie season, while recuperating from an injury, Hertl posted on Twitter about his comeback process, something most athletes do, except that when he did it, the result was one of the most pure pieces of social media ever produced. (Second only to the complete oeuvre of Joe Pavelski’s grandma; the Sharks are elite in this realm.) “Fun must be always” became something of a beloved battle cry.

Today after exersice...i have a lot of new young friends:-D..fun must be alwalys:-)) pic.twitter.com/oM005RF2Py — Tomáš Hertl (@TomasHertl48) January 31, 2014

During the 2014 playoffs, a teammate introduced Hertl to the wonders of Dave & Buster’s, and soon their hotel room was home to some new large stuffed Ninja Turtle and Minion friends. I’m not sure when exactly this spritely jig GIF was originated, but it also doesn’t matter, because it, like Hertl, is timeless. In 2016, a few months after my Hertlborn son arrived, I watched his spiritsake score six goals and add five assists in 20 playoff games as the Sharks advanced to the Stanley Cup final.

Hertl was ultimately injured in Game 2 of that series and San Jose lost to the Penguins in six, but right before all that happened he shared his life’s outlook with reporters at media day.

“I like to be smiling all the time,” he said. “Some guys back home [say], ‘You smiling all the time, just give me break! I don’t have time for smiling.’” Hertl shared his response to those people: “OK, I just like it guys,” he said. “I can’t. I can’t stop it.”

And he hasn’t. Hertl smiled when he promised after Game 5 of the first round against Vegas that the Sharks would be back home for a Game 7 because “we are a better team than them.” To say he smiled when he scored the (shorthanded!) double-overtime goal in Game 6 to make good on his word would be an obvious understatement, except that to him, somehow, it’s an overstatement: “I was really tired,” he said after the game. “I couldn’t even celebrate.” You be the judge!

The San Jose coaching staff and Hertl’s teammates downplayed his “guarantee,” not wanting to give the Golden Knights too much ammunition. “It was an emotional guy with English as his second language,” said head coach Pete DeBoer, “just professing his confidence in our group.” Logan Couture, who, like Hertl, has scored nine goals this postseason and who remains as droll as ever, quipped that “His English is a little broken. … It’s tough for some of us to understand him sometimes.” As for Hertl: “I guarantee we will try our best,” he said before Game 7. “Game 7 is the most fun game you can play in the NHL.” So far this postseason, the Sharks have won two out of two.

Hertl’s childlike whimsy sometimes overshadows the real impact he’s had on his team and on the league. His breakout game against the Rangers in 2013 basically ended New York backup goalie Marty Biron’s career, and yet the veteran netminder was so taken by the charming youth that he sent him a signed stick to commemorate the night. And while Hertl’s showy fourth goal that night wasn’t “big” in a scoreboard sense—the Sharks had already run away with the game—it would nevertheless grow enormously meaningful.

The following day, Sharks veteran Joe Thornton overheard reporters asking one of his teammates whether Hertl maybe should have toned it down a bit given the lopsided score. “Shut up,” Thornton interrupted. “Have you ever played the game? I’d have my cock out if I scored four goals. I’d have my cock out, stroking it.” (The only writer with the, uh, stones to report on Thornton’s now-treasured comments was the late, great Jason Botchford, who got some heat for doing so but was, of course, right.) It’s not every day that some silly, dangly rookie would get this sort of high-level defense from a legend, but not every player is Hertl.

Time marches on, and Hertl is now 25. Last year when I went into labor with my younger son, everything was different: There had been no need for a birthing class this time around, because I already knew how to growl in a calming manner and how to roll a tennis ball around the small of my back for relief. But that didn’t mean I was necessarily prepared; I’d found no time to do meditative things like set intentions and gather special trinkets, and I hadn’t even packed a bag. In comparison to 2015, when I reclined for hours, chanting mantras in my Hertl shirsey—a powerful prenatal blend of earth mama and NHL superstan—in 2018 I spent the majority of early labor sitting in a coffee shop, wincing periodically during early contractions as I raced to finish an article about another celebrated teenaged skater, Tara Lipinski, before the baby arrived. No disrespect to Tara, but it just wasn’t the same.

I called my husband, told him it was all happening, and asked him to look around for the Russian doll and the candle holder and the teal V-neck T-shirt with the shark on the front and No. 48 on the back. Even if I didn’t wear it, I at least wanted it to be in the room, with its happy memories and its silly history. And once again, it worked: Everything was an earnest and babbling and exhausted and thrilled blur, just the way I hoped.