On ice skates I (left handed and left footed) find it easier to come to a prompt stop with the left foot forward, and I naturally slide across ice and such with my left foot forward so, naturally, I thought I'd have the left foot forward while snowboarding.

Everything felt absolutely right, UNTIL I gained some real speed for the first time. Nope! Suddenly everything felt wrong, and I instinctively turned so I had my right foot forward.

So weirdly goofy it is.