Oh, believe me, I've fallen in more than once. One is not doing one's most rational thinking in the pitch-black middle of the night, and BOY did it piss me off.
Thinker hit it on the head, though. The toilet seat isn't what you're really fighting about. You're fighting about respect, autonomy, whose agenda will prevail, caretaking .... the whole ball o' wax.
Excellent Spouse and I were discussing this over drinks (I don't know what that says about us, that we were discussing *toilet seats* over cocktails .... but I guess since we discussing a *philosophy* of toilet seats, that makes it respectable, no? grin) Anyhow, he went through a period where he was *really* negligent about seat-normalization, and he used to say (the essence of) "If you want the seat down, you put it down." That didn't sit (har har) too well with me at the time .... but in reflection I came to agree with him. It's not his job to take care of me in that way. Now, if he thinks of it, lovely, and I appreciate it. But it's my butt that's going to hit that cold, questionably-sanitary water at o'dark hundred. So it's my responbility to engage in self-care by *checking* the status of the seat. Getting mad at him because he didn't remember to take care of me when I obviously couldn't be bothered to take care of myself seems ... really asinine and immature.
That's a lot of words for something really petty, but I think it's a concept that could be quite gainfully upsized to a lot of marital issues.
"Show me a completely smooth operation and I'll show you someone who's covering mistakes. Real boats rock." -- Frank Herbert