That reminds me of a point in my life when I decided to never step on cracks (to counter the effects of people who were not aware), it got to the point where I would not take a downstroke on a bike pedal over a crack, and ended up synching with the sidewalk tiles. Disclaimer: I was at the time, and for most of my thinking life really, caught in a struggle between atheism and extreme magical thinking.
Oddly enough, I still semi-consciously adjust my gait on tiled floors with any pattern to them. That's nothing to do with being unable to multitask, though. I wonder if there are any interesting correlations with walking tics...
I personally have a tough time filtering out inputs, and find my attention forcibly split between paying attention to nearly everything whether I want to or not. This makes me act and plan more linearly than is optimal, and is horrible for crowded rooms, but otherwise doesn't disable me. Also, I have a strong dislike of the action of chewing gum. I was recently joking about not being able to walk and chew gum at the same time, and I wonder if it might actually have some truth to it? I would like to know everyone's (but especially people with similar filtering issues) habits regarding gum.
How often do you chew gum?
(The poll is in the first comment.)