Superstition is an interesting thing. As a kid, I remember playing Dragon Warrior on my NES and being impatient, I'd often tap the button to get through combat messages as quickly as possible. I made a little game of it, trying to time my taps in rhythm so that I'd get through the combat as fast as possible. Of course, sometimes it seemed that I'd get critical hits more often when I did that, so eventually I started tapping the button rhythmically to get more critical hits. (In reality, it was probably survivorship bias, where I noticed the critical hits more when I was doing the tapping than when I wasn't. Also interesting to note that the later Super Mario RPG games would require you to tap the button during combat for extra damage/defense/etc.) But, in my mind a superstition was born.
Of course, MMO players have superstitions as well. And plenty of them.