Facebook, what's the point?

Against my better judgement, I joined Facebook yesterday. I cancelled my membership today. Maybe it's just for teenagers, but I just don't get it. Are we all so insecure that we need to know exactly what our friends are doing, and even what they are thinking? I was going to use it to allow old friends to contact me, but I think I'll stick with Friends Reunited. Who chose to have things like a "poke" and "spanking" on the site? Employers often look up potential staff on Facebook, so watch what you put on it, or you may not get that job you wanted.