Whats worth knowing

Something that is worth knowing is how to defend yourself.  You never find out that in school.  What if someone breaks into your house?  How are you going to deal with that?  School is not helpful because it doesn't teach you that.  It teaches you how to yell for help but what if no one is there to help you.  Why won't school help you with that?  Another thing worth knowing is how to read another persons face so that you know whether someone is sad, mad, happy etc.  It would help you when you get older if you are going into an area where you need it.  Also it would help gamblers.  I would like to be able to read faces and school doesn't teach you that.  Also why don't they teach you how to keep a straight face.  It's really hard to keep a straight face when you are trying not to give something away.  For example,  when you give someone a birthday present.  You try to keep a straight face because you don't want to give away the surprise.  These are all worth knowing but are not thought in school.