Had a 5-hour meeting which started first thing in the morning. (Okay, 10am, close enough, whatever.) It was in another building, so I decided to drive and park there instead of stopping at my desk first.
In order to do this, I only had to do one thing this morning: Bring my laptop's power cord, so I would have enough juice to last the whole meeting.
Of course, I forgot.
Had to walk back over and get it.