I don't generally engage in conversation with my seatmates (usually sleeping, or we don't share a mutual language, but I did have a lengthy conversion earlier this year with an interesting seatmate) Flying to Turkey both my seatmate and I were dozing after long haul flights. We both got up to use the loo and started talking about our flying schedules. That led to a discussion about Turkey and then a discussion about the 'Europe' forum here on FT and how so many North Americans seem to mistakenly believe that Turkey is in the Middle East. (Disclaimer that he resided in North America although from the UK, and he brought up the subject!)

(Note that the destinations forums here on FT were renamed shortly after that conversation)