For me, it's usually the 5:00am mornings when I *should* be getting in the shower and then suiting up to ride in to the train but where I instead hit snooze 3 times, make myself a coffee, and drive to the train instead.
Then there are the times when I know I have the free time to put in an extra 10-20 miles but turn around and head home because riding solo is so freakin' boring.
I am the BF resident wuss.