Is it normal to like a guy you hardly know?

Basically its kind of a facebook thing. This guy sent me a friend request and we started talking I really liked him at first - extremely attractive guy and an okay personality aswell. Eventually he asked for my number and I gave it -_- After that he wanted to ring all the time instead of texting, he kept being immature over small things like me not picking his phone calls up. He would talk to me randomly here and there so I didn't bother with him either - seemed like he had changed since I gave him my number. A few months later I had started talking to this other guy - who happend to be #Guy1's brother.. His brother started to like me a lot. When I realised they were brothers I told Guy2. He asked me how I knew guy1 so I told him 'through fb'. His brother (Guy2) then told me that Guy1 has had a gf since a year and nearly all his mates have his password to his account. I asked his brother for the last digits of guy1's number just to confirm it was him.. But according to his brother it was not guy1's number & it was his mates :@ which really pissed me off as you can imagine how much I liked guy1, but apparently I had been talking to his mate all this time and not him. Now that I think about it the guy that I had been talking to and fb had seemed so much nicer compared to the one who had my number. The problem is I don't know if his brother was just telling me the truth as he says he likes me A LOT. But the thing is I don't like his brother - I still like Guy1 and can't stop thinking about him although he sounds really immature and theres a chance that he may have given my number to his mate instead. :/ Helppp, SO confused! I'm trying to forget them all and all this drama but I can't seem to get Guy1 out of my head! I still want him so bad & I don't know why?! Usually I don't let any guy in my way. Ever.