I try to commute by bike as often as possible, but sometimes I need my car to move equipment around, pick something up after work, get to an appointment quickly after work, etc. The rest of the time, I fight laziness, just like the OP. However, every time I force myself to get on the bike, no matter how cold it is or how tired I am, I am thankful that I did. Ultimately, work has become (as another poster put it) "the thing I do in between bike rides." Force yourself and let me know if you're ever sorry.