I seriously thought I was socially incompetent/uncool/whatever when I was young because my main extracurricular was hockey and I was usually the loner on my teams--didn't get along with folks, didn't share any interests, didn't want to do anything they wanted to do, just weren't on the same wavelength. I stopped playing organized hockey after my sophomore year of high school and was my class president when I graduated...realized that I wasn't the social idiot, it was my teammates who were.
(ironically, right after quitting I met a guy who would still be my best friend two decades later, and he was very much a hockey lifer growing up and who I would have been teammates with the next season had I not quit when I did)