A fable and a profound worry

In Chapter 13 of the Sandman Companion, Hy Bender prefaces the discussion on inspiration with the following allegory:

There's a fable about a bird being asked which wing he lifts first when he's about to take off from the ground; and the bird, who's never given the process a thought, becomes so self-conscious that he loses the ability to fly.

I feel a bit like the bird at the moment. Thanks to the simplest, most trivial, most innocent comment, my entire world has been thrown into disarray to the point where I'm almost completely unable to carry out the most basic manual tasks. What could possibly have caused this catastrophe? Someone pointed out to me that I used the wrong hand to enter numbers into keypads.

Suddenly I've become acutely conscious of the fact that I switch hands from left to right and back with no apparent rhyme or reason for the change. I've started to worry that somewhere along the line, my attempts to analyse the situation have broken some fundamental part of my brain that deals with handedness. I'm concerned that, now that I've noticed the problem, I'm never again going to be able to return to my previous, happy, delusion of being right handed.

The more I think about it, the more bereft I feel. As though someone has taken away one of my fundamental certainties...