I started commuting by bike 42 years ago at age 15 to my first job and have done so ever since.
Reasons for starting:
No license
No car.
Broke.
Hated bumming rides and being dependent.
As a teenager I was a counter-culture, anti-authority, eco freak, long haired, hippie who loved drafting the school buses to high school and showing up virtually everywhere on a bike.
I love the feeling, the exhiliration, the rush of riding a bike.
Reasons for still commuting after 42 years-
I got really fast and fit on the bike and there's a certain kind of pride and vanity involved that I can't seem to jettison.
I HATE SITTING IN TRAFFIC IN A CAR. It feels like the biggest waste of time, resources and money ever.
I'm cheap and it saves me tons of money.
For about an hour and a half of each working day I feel like I am on vacation.
I love the feeling, the exhiliration, the rush of riding a bike.