At 8 years old I was able to expertly dismantle many radios.
Was still a few years away from reassembly.
I was doing that at three or four and was reminded of it constantly for the next ten years or more. (I actually raised the subject on my mother's death bed.)
At 8 years I recycled filesystem directories. I didn't know you can create new folders, so when I needed one I grabbed a random one from C:\Windows, moved it to my desktop and deleted its contents.