I guess I fall into the boy who never grew up. I cant use all my old trade experiences because I no longer have access to machine shops or welders. But, I can mechanic and "Rube Goldberg" as well as the next guy. Another hobby of about 3 is RC electrics (Model Aircraft) learned a lot from that too.
I wish I had an old "Harley Davidson Bicycle" (in excellent condition) I seen in 1958 stored in a friends stair well. That bicycle must have weighed 75 Lbs. with front and rear suspension. I don't think a China Girl could power it.