So do you use your right or left thumb to press down the spacebar?

I don't really pay attention to what thumb I hit the spacebar with, but now that I'm typing something out, I realize that I always hit it my with my left thumb. Never my right. Odd. I'm right handed, and yet I seem to do the majority of the typing on the keyboard with my left hand. I believe I can type up to about 120 WPM, but I rarely get up that high in day-to-day typing. I vaguely recall taking a class in middle school, but I'm pretty much self-taught.

Jam it back in, in the dark.