Tom Brady turns 40 next week, and the sports world is acting like a dog is going to win the Indianapolis 500.

Come on! It isn’t so crazy. Speaking as someone in his 40s, let me confirm that 40 isn’t that decrepit. It’s barely halfway to dead! Brady is undoubtedly special, and football is a dangerous game, but all around us, there are miraculous 40-year-olds who can still put on both shoes in the morning, who can download a podcast, who can make an emergency turkey sandwich at 2 a.m. and not wake the entire family.

There are even a few who can explain Snapchat.

Age is purely a number—the cliché has never been more true! Today I know butt-kicking 80-something men and women, 70-something triathletes, 60-something runners, and a whole bunch of CrossFit-sculpted 50-somethings you don’t want to get trapped in a conversation about CrossFit with. The one and only Kirk Douglas is now 100, and I am certain I would lose an arm-wrestling match to 100-year-old Kirk Douglas.

Did you see those recent photos of buffed-out Amazon kingpin Jeff Bezos? Mr. Prime is in his prime: At 53, and now the world’s richest person, Bezos is completely jacked, a total biceps gun show with free two-day delivery. (I probably would still favor Warren Buffett in an arm-wrestling match, because who bets against Warren Buffett?)

Business thankfully doesn’t (always) kick its aging to the curb, but sports has a weird time wrapping its brain around the older athlete. We see a guy like Roger Federer capturing Wimbledon again, and we hail it as a clock-defying miracle, as if Wilford Brimley won a Grand Slam.

At 53, Amazon’s Jeff Bezos is completely jacked. Photo: Rob Latour/Rex Shutterstock/Zuma Press

Federer is 35! Thirty-five is a sweet spot of life. If you gave an ordinary person the ability to permanently lock into a certain age, 35 would be a top choice. You’re old enough to have accomplished a few things, and you’re young enough to not frighten everyone when you take off your shirt at the beach.

(I’m confident no one would pick being 25. Twenty-five is the pits. You’re insecure, underpaid and probably still sleeping on a smelly futon. Plus all the older people in the office despise you, because in you, they see their own demise. I know I feel that way about the 25-year-olds at the Journal. They can all go work at Instagram, or Cold Stone Creamery, as far as I’m concerned.)

None of this is meant to knock Brady. He’s exceptional, and has been for his entire career: the late draft pick turned back-up turned sudden superstar who has ascended the football mountaintop. He leads an enviable life of fame, success, money, love, family, and mumbly conversations with Bill Belichick.

And, generously, he wants to share his secrets. As Brady has gotten older, he’s begun to style himself as an anti-aging guru, selling dietary supplements and fitness doodads and even magic space pajamas that cost as much as a plane ticket to Chicago. Brady’s morphing into a fusion of George Clooney and Jack LaLanne. I’m confident that in 50 years, we’re going to turn on the television (or whatever television is—television’s probably going to be gone in two years) and see a 90-year-old Tom Brady yanking on resistance bands and yelling at us all to get to the gym. On Mars.

I’m also confident a 90-year-old Tom Brady will be playing QB for the Jets.

Tom Brady gestures during an event in June. Photo: Eugene Hoshiko/Associated Press

This isn’t to say there aren’t downsides to aging. It’s true that as you get older, your body changes, and you probably need to take it easy on the peanut butter pretzels. If you drink sugary cocktails, you’re going to wake up feeling like an elephant is sitting on your head. You’re going to read a lot of articles about Bitcoin and Ethereum and be completely confused.

Meanwhile, you have weird, obsolete old person habits. You have a DVD player. You can navigate a car—a stick-shift!—without checking Google Maps. You leave and listen to voice mails. You care about cable news. You’re reading this in newsprint.

And you start to lose your fashion sense. One of the most popular articles the Journal has published lately offered style advice for men over 40. Apparently, once a man turns 40, picking out clothes starts to resemble juggling nuclear fuel rods. For the love of mankind, don’t wear the cargo shorts!

I don’t think this is a reason to be fearful of aging. Nobody looks good in cargo shorts.

Tom Brady is going to be 40, and I think we should tell him the truth: he’s only getting started. Life only gets better from here. There’s fun, there’s family, there’s Viagra. If not, he can always lounge on the couch, eat a turkey sandwich and watch football. That’s good, too.

Write to Jason Gay at Jason.Gay@wsj.com