On a day that you have been looking forward to as a personal goal. To have commuted every day this week, and commute straight to the gym to do a spinning class after work, then ride home, something will go wrong with your light system, thus stranding you at work, forcing you to call the wife.

I don't think there is anything more frustrating than when something small and for the most part, out of your control, gets in the way of attaining personal goals.