I used to take apart nearly everything to see how it works and then put it back together. Computers, cars, clocks, vacuums, electric tools, DVD players, doorbells, telephones, remote controls, stereos, toasters, microwaves, ceiling fans, gaming consoles and controllers, instruments, etc.; I don't do it too much anymore though since I pretty much have an idea of how most things work now. Usually if I see something that I want to take apart these days I can't because it's not mine to mess with