I got into Pokémon when the card game and anime first came to America. I was in jr high school at the time and collected so many of the original cards. Never finished my collection, though.
I got into the Pokémon craze at first, but stopped following it in my later years of high school. I was too busy preparing to be an adult, so I set it aside and forgot about it for years. I didn’t even know there were more than 151 Pokémon until over a decade later.
I learned some of the newer generations with Pokémon Go, but I still remember all of the original 151 Pokémon. The newer stuff is just weird to me.
EDIT: I never got into the games, even though they started releasing when I was a teenager. Pokémon Go was actually my first game in the franchise; although I watched my friends play the classic Red and Blue games back in the day.