I'm a bit upset at how little hardware stuff I'm doing these days. When I was maybe eleven or twelve, I dreamed of being an inventor. Not as a profession -- couldn't care less about that -- but as a hobby thing. Still do, sometimes, but hardware is expensive: motors aren't cheap, and modern electronics are too proprietary that it's almost impossible to salvage parts from them.
Well, being eleven or twelve I was also deathly afraid of the dark (don't lie; you were too). So before bed, instead of hitting the lights and running across the (EVIL DARK) room to the safety of my bed, I created a pulley system; I tied a chess piece to an ethernet cord running along the side of my door, and tied some string to the knob, looping it around the chess piece like a pulley and reaching my bed. So I'd leave the door open to allow the hallway light in before shutting the light of my room, and then, safely in bed, I'd close the door by pulling the string.
But any real hardware was a bit on the expensive side, so I stuck with software. Software's great; everything you'll ever need to create professional-grade anything is online for free. Never need a tutor because every technical issue ever is online, at StackOverflow or what-have-you.
After middle-school, though, I was a bit upset at having left my dreams of engineering in the dust, so I tried something in freshman year of high school. I tried to build a turbine.
So I found an old empty tissue box as the chassis. There was an American flag in my closet (they would appear on our doorsteps on Independence Day, for some reason), and I stripped the flag off for the pole. It was a small, wooden one; worked nice as an axle. Took some paper and cut-taped it to make a little fan-blade thing, and attached it to the axle so it spun pretty nicely. And then, a candle inside the tissue box.
The idea was simple; I'd light the candle, the fire would build steam inside the box and move up through the hole in the tissue box to spin the blades on the turbine. So I lit the candle.
It set fire. Really, really fast.
My backyard filled with the smell of burnt paper and it was all very funny and I never tried it again. But it was all very nice and I wish I did.