Bike commuting isn't for wimps. It's fraught with peril. Danger lurks around every corner and you never know what's coming at you next. You have to be aware and vigilant at all times.
I keep street clothes hanging on the back of my office door, which is usually wide open. I closed it for a few minutes this morning because I had to make a sensitive phone call.
As I was dialing, I turned my head slightly and my peripheral vision picked up a tall, human form standing at my door wearing a black shirt.
Damn thing scared the crap out of me.
If I'd had a bike helmet hanging on the top hook, that dude would have looked six and a half feet tall.