I got over all that shy/recluse stuff years ago. I'm often a vendor at art shows, and find myself having to talk to customers and fellow vendors all the time. While I haven't flown in . . . 5 years (?) and usually don't fly alone, I have no problem talking to strangers. Usually they have to start it, or they and I have to make eye contact in reaction to something, so you know they're willing to talk.
Recently I was at a Scottish Highland Games exhibition, and sat down with some lunch to listen to a band - the woman next to me gasped, then said she was a vegan and horrified by the sight of my bbq pulled pork. I apologized and offered to find another place to sit - she said it was okay, I could stay, she just couldn't look at my food (well I didn't ask her to look at me while I ate, did I?). I did eat quickly, and tried to turn away from her out of respect, but that woman ended up talking my ear off !
She never shut up.
I finally caught some pork between my front teeth and left it there.