[smileysteve]

The biggest pro of a bike is it teaches you to read the road and traffic ahead for energy conservation (and defensive driving).

On a bike, this mostly reduces pedaling; in a car this can reduce unnecessary braking, safer driving distances, which make you a more predictable driver.

[globular-toast]

It also gives you a lifelong respect for people so if you do drive you won't treat humans like annoying obstacles that might ruin your paintwork if you hit them.

I believe 100% that nobody should be allowed behind the wheel of a motor vehicle before obtaining cycling proficiency.