So: here's a pair of my (related) eccentricities.
I think sometime in 2011, I noticed that when I was trying to verbally explain something that was complicated or in depth, I would close my eyes while I was doing it. This is probably to block out visual stimuli that I find distracting: this lets me focus on what I'm saying.
Put differently: I can think and talk at the same time -- but not think, talk, and make sociable eye contact with another person.
When I'm doing this, I also tend to gesture with my hands a lot.
The other thing I do -- which I think I've only done in the last year or two (i.e. early 2013?) -- is that when I'm thinking really hard -- and particularly when I'm thinking really hard AND having to explain it to someone -- I have to take off my glasses, close my eyes, and lie on the ground on my back. I still gesture with my arms as I talk.
This is probably an extension of the above tendency to shut my eyes: I lie down because I'm using all my processing power to think something through (or: thinking it through while explaining my reasoning). I don't have enough brainpower remaining to keep my balance and remain upright: I need it all for thinking.
I engage in both of these tendencies only at work: the "closing my eyes" thing about once every two days; the "lying on the ground" about once every 2-4 weeks. Apparently nothing I do at home requires this degree of deep, intensive thought.