It's interesting to experience your brain relearning a habit that has become so ingrained. Reminds me of the Smarter Everyday backward bike episode [1]. In fact, I just tried to tie my old 2 loop knot and accidentally tied Ian's knot again.
My only issue is in keeping the starting knot tight. I usually use the standard shoelace knot which makes it easy to keep tension on the lace at all times, and that keeps the starting knot tight. But I'm finding with Ian's fastest knot I lose tension when I'm pushing the two loops towards each other, which causes the starting knot to loosen slightly. Is that something that can be solved with more practice?