What is the purpose of facebook?

[faithfulbattle945]

My friends told me that I should start a facebook account so they can "befriend" me there. I looked at it and see that most people on there are out of their mind. Like this girl from my class who is at best average looking would post pictures of herself posing...and on fb she actually looks decent. In real life not so much. Or people changing their pick every other day...........my question being: why even have a facebook? I wanted one, but I worry that this may make me look like I'm one of the herd. Basically someone with a low self esteem but pretending I got it all together and my life is fabulous. Any thoughts on that? Why do you have a fb if you do?

btw. I'm 25 yrs old. I know there are people on there older than me, idk why I feel like it's high school all over again.