Don't talk to Richard Sherman about Mew.

It seems that the elusive 151st Pokémon may represent one of the darkest times in the Seattle Seahawk cornerback's young life. When he spoke to Mashable about his love for the gaming franchise, Sherman almost didn't reveal the "most frustrating moment" of his time playing.

Twenty-seven-year-old Sherman has been a diehard Pokémon fan since the original Pokémon Red and Blue came to America in 1998. He spent plenty of time playing the Pokémon trading card game as well.

"At the beginning, I would trade pieces of candy for my best friend's doubles," he said. "I ended up with a lot of Weedles, Caterpies and Growlithes, but my goal was always to get a holographic Charizard."

The passion for Pokémon led him to the Game Boy games — Sherman said he always picked Charmander as his starting Pokémon — and into the Nintendo 64 release of Pokémon Stadium.

"I always had Pokémon Blue and Yellow with me, and was always ready to trade," said Sherman, who took the "Gotta catch 'em all" mantra to heart. "I got even more excited when Pokemon Stadium came out. All of the Pokémon were finally in 3D, and it was awesome."

In the quest to collect all of the original 151, Sherman — like other Poké-fans at the time — was desperate to get his hands on the rare, psychically charged cat Mew. Toys 'R Us ran a promotion in which anyone who brought in a ticket stub to 1998's Pokémon: The First Movie to a store could download their very own Mew.

"I got my Mew to level 65. It was pretty unstoppable," said Sherman. But after he and his brother had a fight, his brother struck back by creating a new save file on his Pokémon game, effectively erasing all the old data. And little Mew.

This was before the time of cloud saves and back-up hard drives. Back then, losing a game save was permanent — and devastating. "That was hundreds and hundreds of hours of work into that game gone, and there was no way I was able to even get another one."

But that didn't put Sherman off Pokémon for good. He still plays on his DS on the road, and will even trade and battle occasionally with his teammate Doug Baldwin, Seahawks wide receiver.

That continued love explains how Sherman got involved with promoting the series' upcoming 20th anniversary on Feb. 27, which even got its own Super Bowl ad spot Sunday night.

"The game is incredible, and intense, and takes such dedication," he said. "It really sets you up to train hard for things later in life."