One thing that I really can't stand is people who make something out of nothing, especially in the case of men and women. A girl who is standing across the room smiled at you, so WHAT? It could mean ANYTHING! She may even be smiling at someone else! Either way, if you like what you see, it is not against the law to go up to some girl and talk to her; so why make yourself crazy over body language and the like.
One thing that I really can't stand is people who make something out of nothing, especially in the case of men and women. A girl who is standing across the room smiled at you, so WHAT? It could mean ANYTHING! She may even be smiling at someone else! Either way, if you like what you see, it is not against the law to go up to some girl and talk to her; so why make yourself crazy over body language and the like.