As everyone probably knows by now, I am pretty much an expert on this subject. So, I am going to give you a little bit of advice on how to get a man you have previously met if you are in one of his classes.
DO:
Girl: *Walks into class on time and sits next to man* "Hi, *******. Do you remember me?"
Man: "Of course! You're *********'s really attractive cousin!"
Girl: "Yes! Yes, I am!"
Annnnnnd eventually they get married and have lots of little babies.
DON'T:
Girl: *Walks into class late and sits at a different table even though there is an open spot right next to Man*............*Stares creepily at man throughout class*...............*Leaves class without talking to Man before class is over*
This will make him think that you don't actually remember who he is and will cause him to never come sit by or talk to you.