I remember trying to get into the Metroid games many different times when I was younger but could never do it. It was too boring and impossible for my child brain to comprehend, so I just figured I despised the Metroid series and other Metroidvanias alike.
Fast-forward several years later and now I'm in love with the Metroid series and have pretty much 100% completed most games in the series, and Metroidvanias are up there amongst my favorite genres. I would punch my kid self in the face if I could for not sticking with it and experiencing these games sooner. I <3 them games with all my <3.
So what about you all? Any games or genres of games you weren't particularly fond of at first, only to become hopelessly infatuated with later on in life?