Related: I used to have a much bigger problem tabling arguments, even if I really needed to be doing something else. (Especially pernicious if you're part of a college debate group where people think nothing of staying up til 3am talking, even if you have glassblowing class at 8:30am).

I felt like saying "I really have to go to bed, or I'll burn myself in the morning" was tantamount to "You're so much better than I am, but I'm too much of a coward to admit I'm begging off." So, what I did was to visualize the worst thing that would happen as a result of leaving the fight. In one case, I imagined my interlocutor, D_, emailing all our friends to say "I was arguing with Leah about how well fleshed out the female characters in Assassins are and she ran away because she sucks!"

One I said that explicitly to myself, it was pretty obvious that D_ wouldn't do that, and, even if he did, our mutual friends would think it was the email, not my going to bed, that was weird. And then I went to bed.