Anyway we didn't know the guy too well, lots of getting-to-know you type stuff. The MMA fighter after a few hours mentions that he was really into Starcraft, Age of Empires, and other RPS.
You could have knocked me and my other friends over with a feather. This ripped "jock" likes Starcraft! Oh my god! We were so surprised and just went on and on about how impressed we were like idiots.
A year or two later one of my friends who was there (a little more balanced guy who played more sports and hung out with more varied groups of people) told me that he and the MMA fighter had been talking as we walked back from the bar. The MMA guy was apparently like "so I guess these guys have just never hung out with any athletes?" Turns out it isn't that abnormal for them to like cool and nerdy stuff.
Even though I felt pretty dumb, that was a good experience for me as a person. My whole life I've been a pretty accepting and nice person, and my intelligence has never really made me feel superior to other people. I guess to that point those qualities made me feel like I couldn't possibly be prejudiced or biased because hey, I don't actively hold any hostile or condescending beliefs. But that showed me that my own ignorance was sufficient for me to classify some guy I knew almost nothing about and put him in a box, a guy I liked perfectly well and never had a bad thought about. It's a tough thing to be aware of but I think has made me a little more skeptical and humble, which I'm glad for.