This didn't come up in my household recently; it was mentioned in an episode #4 of 'Man & Wife'. Scoop left the toilet seat up once and his daughter fell in. Shanda and his daughter were both angry at him for quite some time over that. That story got me thinking about my own "battle of the toilet seat" from early in my teenage years.
My dad remarried when I was 15, and his new wife had a daughter one year younger than me. My dad and I moved into their house, and the daughter and I shared a common bathroom. Up until this point I had never had to share a bathroom with a female. I soon learned all about skivvies and whatnot left over the curtain rack, the wide variety of primping materials scattered around the sink, not to use her blow dryer and to be very careful around the curling iron. I also learned that women aren't too keen on you leaving the toilet seat up after having a wizz. In the typical teenage boy way, I pretty much ignored her complaints until one day when she had one dunk in the ti-d-bol too many. There were screams and death threats that day. Her mom was on her side, and my dad suggested that I make an effort to be more mindful thereafter. So I learned to reflexively put the seat down whenever I was done with the bathroom and it's stuck to this day.
Here's the question I have. If it's "not that hard" to learn to put the toilet seat down when you finish, and "any moron can do it," then why the fuck is so hard to learn to look at the seat before you start? It seems to me that's a skill that everyone should develop, just in case you find yourself in a situation where... oh, I don't know... someone else left the seat up? I do know this, in all the years that I shared a bathroom with just guys, I only fell in the freakin' toilet one time, and that was because I was tired and my eyes were on the fuzzy side. It woke me up quick and reinforced the notion to look before you squat.
So guys, learn to put the seat down when you're done. It's the polite thing to do.
But ladies, learn to look where you're planting your butt, just in case.