Originally Posted by
narvik
Aye. As an inexperienced flyer one might make such a faux pas through lack of knowledge. As an experienced flyer one might make such a mistake through some small, unexpected change in one's common routine.
I fly 125-150 legs a year and I am good for at least 2-3 experiences of sitting in the wrong seat. This takes the form of two mental lapses 1) I usually book 2E and I will sometimes sit in 2E even if I should remember that I am in some other seat on that flight. Or, on 757s when boarding from the middle I will sometimes mess up counting "down"/"up" on row numbers and sit in the row behind where I'm supposed to. Fairly embarrassing but it happens frequently enough that I can't claim that it is a one off experience.