What happened when you realized you are "that guy"? I'll start.

Today, I was at school after nordic ski practice. We have no snow yet at school, so I had my rollerskis with me. So I decided to ski home. The streets were a little icy and wet, but I was able to ski quite easily. As I was skiing along a rather busy road with my backpack on, I realized I was that guy. The one who uses a piece of exercise equipment to commute.

But I'm sure reddit can top it, so lets see!