Ok, this isn't an exhaustive list. I don't think we have time right now. However, today I was feeling extra dumb. You know the day, you feel slow, your timing is off, it seems like every decision you make is the long way. That sort of thing.
Well I came out of work this evening only to discover that in my infinite dumbness, I hadn't actually locked my bike to the rack. It spent 8 hours out front freelocked. The funny thing is, there was a 3-speed in the rack that'd been there all day exactly the same way.
So, what sort of stupid things have you done on your dimwitted days?