I'm 27, and commute via bike several days a week. (Mon & Tues of this week so far). Most of the fellow commuters I see here are older than me. My morning ride is 8.5 miles, but I take a shaded MUP path home to the tune of 11 miles.
I don't ride every day, as I have crappy knees and like to give them recovery time.
Has anyone else noticed that they don't ride for pleasure once they start commuting?