I have cycling shorts, but I don't always wear them. Yesterday, I'm out on my road bike, stopped at an intersection, waiting for a break in traffic. I'm wearing regular baggy civilian shorts. There are two girls on mountain bikes just behind me also waiting.
So, there's enough of a break that I think I can scoot through, and look very professional while doing it (even at 54, my instinct is still to impress girls with my prowess, I guess - like young women would really care or even notice!). I start out to go with my relatively fancy-looking road bike and its SPD pedals. But instead of going, my pant leg gets caught in the saddle somehow as I'm remounting, or maybe it was on my pump mounted on the seat tube, I'm not sure at this point. I end up not moving forward at all, because as I was trying to execute this maneuver quickly, the pant leg problem ends up making my foot miss the pedal entirely and instead of going forward, I half fall over to the pavement. What a dork!
This is why, even a somewhat pot-bellied 50 year old Fred should cycle with the proper cycling gear unless riding a beach cruiser.