Why bike?

So this week I managed to take the train to work 3 times. And instead of driving to the station, I rode my bike. My goal is to do this about 20 times this summer, thereby saving about 3 tanks of gas or about $120. Biking there is not a problem. It's about twenty minutes down hill. Biking back takes about twice as long and ten times as much effort. Not only is it uphill, but on windy days it's straight into the wind. I'll have to admit that about a third of the way up yesterday, I was telling myself I was crazy for doing this. Motivation? Mostly the money savings, a little of the green thing, (though when did bikes become a green thing?) Third exercise. I shouldn't be that winded after that short a ride. Fourth, it means I need a little more time in the morning so Wifey needs to do more of the baby prep in the morning and the pick up.