I also am left handed, and also have a tradition of sitting on the left side, in a window seat. Very rarely have I sat on the right hand side of the aircraft. I also have a tradition of drinking coke on flights rather than other choices. I don't know, it's just what I got used to and find it relaxes me to be in familiar surroundings and drinking something familiar as well.
On my upcoming trip DFW-IAD, which seats did I choose? 737-522 is 13A. A320 on the way back is 17A. You should have seen the look on mother's face when I told her row 13. She hates flying, and that was kind of a slap in the face. Oh well, she's not the one flying, and it's close to the exit. It was also the only window seat left.