Why girls accept random guys on Facebook?

[Rebelnature]

I don't really understand how girls operate. I know not all girls are like this but im a 21 year old uni student and my friens went on my account as a joke and added random girls. Fair enough they go to to my uni but still some dont even go to my uni and we have as little as 2 mutual friends who i myself dont even really no anymore. I asked them to remove me as friends and like they never did...

Yet...when it came to a girl that fancies me as i found out through a mutual friend who i tried to add she like never accepted so i cancelled the request after a few days. The same thing with another girl who i hooked up with in a club although she did eventually accept. I added her 3 times becuase i wasn't sure if it was her or not. But since then when i see her out she always tries talking to me and say 'hey i know u from facebook' but i ignore her now. Dont like her attitude.

Why are some girls so different?

As a guy i honestly dont give a complete **** as to who adds me on facebook. As long as u aint some freak