Why do girls always come back when they're gone?

I was with a girl a few times everything was going well we were getting on great and I told her I really like her , the following week she started trying to ignore me completely so I just started to move on , only about 2 months later she came back trying to be with me and I was with someone and now her friends who I got on with don't talk to me ,why are women are so confusing or some anyway
Why do girls always come back when they're gone?
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