Rolling, squirming and trying to crawl

I've been trying really hard to learn to crawl lately.

I can get up on my hands, and sometimes on my knees, but never at the same time. My preferred posture is this sort of runners' stance - one one knee and one foot, ready to take off at the sound of the gun.
So far, though, this keeps me from making much forward progress. However, I do move backwards quite nicely! This leads me to some odd places:

Oops! How'd I get under the table?!?
But clearly, I don't mind! I just keep trying and trying.