Fifty-eight year old fixie rider here - no, it's not just for the new-borns trying to gain acceptance with some stylish clique. Been doing about half my transportation miles on fixed gear since the early 1990's. Currently riding a Surly Steamroller. I like the simplicity and the feeling of connection to the bike and to the road, but this is difficult to explain in words to someone who hasn't tried it. Forces me to be more proactive in my interactions with other trafffic, and I am a stronger and safer cyclist because of it.