I spend my days using my brain to make money. As a creative person, all my hobbies rely on my hands... I refer to it as 'grease therapy'. I like to build things out of metal, wood, plastic, fiberglass, you name it.
I learned in my years in the USAF that I can fix anything. As a perpetual tinkerer, I can usually make it better while doing so. And as a person who doesn't make his living doing it, I have fun along the way.