I just learned of an interesting character from the dawn of powered flight: Cromwell Dixon.

At the age of 14, he built (with the aid of his mother) what he called his "SkyCycle," a human-powered blimp - a gas bag with a suspended framework and propeller, driven by pedaling. His mother sewed the gasbag for him, but she let him do it. My parents let me do a few semi-suicidal things, but they never let me do anything nearly this cool.

It probably helped me survive to adulthood, though.