I started bike commuting because of training. I found that if I had to ride the bus home to get my bike, it was more likely that I'd just plop on the couch and never get back outside. So, I'd usually just take a long detour home. The great thing is that if it's a hard day, you can just hammer as long as you want and if it's an easy day you can just take a nice spin directly home. After awhile it just became so natural that driving or taking the bus seemed so lame.

And now that I have kids, I hoard every mile I can get my hands on. Even if I just get a 4 or 5 mile detour on the way home from work, it adds up so I can still make a 100 a week.