Data point counter to the other two replies you've gotten: I -- and, I perceive, most people, both introverted and extraverted -- am neither overjoyed nor horrified to have someone attempt to start a conversation with me on an airplane. I would say that as long as you can successfully read negative feedback, and disengage from the conversation, it is absolutely reasonable to attempt to start a conversation with a stranger next to you on an airplane.
Now, I can't tell if the objection is to 1) the mere act of attempting to talk to someone on an airplane at all, which I can't really understand, or 2) to the particular manner of your attempt, which does seem a bit talkative / familiar, and could perhaps be toned down.
r/Fitness does a weekly "Moronic Monday", a judgment-free thread where people can ask questions that they would ordinarily feel embarrassed for not knowing the answer to. I thought this seemed like a useful thing to have here - after all, the concepts discussed on LessWrong are probably at least a little harder to grasp than those of weightlifting. Plus, I have a few stupid questions of my own, so it doesn't seem unreasonable that other people might as well.