I feel like I can relate to this (a little). I'm no prodigy, but even as a young kid (6 or 7) I would write down algebra problems all day and solve them. I did a ton of mental math, too, writing down several dozen 2-digit numbers and adding them all in my head.

Haven't really thought about that in a long time. Playing with a calculator also got me into programming (TI-Basic on the TI-83 in middle school).