Something weird happened to me the other day: I grabbed my toothbrush with my right hand, the toothpaste with my left hand, removed the cap with my right thumb and index while holding the brush with the other fingers, pushed out some paste onto the brush, and started brushing.<p>Nothing crazy so far, you'd think. Except I've been doing it the opposite way for at least 30 years, i.e. as far as I can remember. And that involved an additional step at the end where I would drop the tube from my right hand and switch the brush from left to right (I'm right-handed).<p>Basically, I've been using a suboptimal process forever. And I'm all about optimization... So how did that happen? And why did I not notice it before?!