Learn to type with all ten fingers (otherwise you look unschooled). Dress up when you go for a plane ride. When conversing with someone, let the other person do most of the talking. These were tips I included in an article I wrote a few years ago, when I interviewed successful career women on the best advice their mothers ever gave them. To this list I added a few examples of my own: Before you date a guy, watch how he treats his mother; and teach your children how to drink wine at home so they don’t make complete asses of themselves in college. (Media Guy’s helpful input: Teach them what it feels like to get drunk and they’ll never attempt it on their own. Ever.)
I came across a few more life lessons you’ll never learn in school. There are 45 of them. Some of them (a lot of them, actually) are a bit too touchy-feely for my tastes. But I do try to abide by #13 and #17.