I've been contemplating one problem of the universe. Ok so it's not really a big problem but it seems to be universal. The problem of how to get the guys to put the toilet seat down. Actually I really did accidentally come across the answer. I was amazed when I realized it. But it creates another problem, no one can leave the seat up without holding it so is it worth it? If you think this is silly-stop reading guys. All females keep reading.
All you do is buy and install a non-slamming toilet seat and have a shelf behind the toilet so the lid hits it and has to remain straight up. This prevents the seat from going straight up and it's off enough that gravity pulls it down! Ha! This way as soon as anyone leaves go of the seat, it goes down by itself!
Now we just have to solve the problem of guys not replacing the paper on the toilet paper roll holder.