Do some people do it on purpose or are they serious?

so these girls that are in my class we are a week away from the last day of school and this one girl named "clarissa" says "here you go boy" when she hands out a paper, then a girl named "sherlla" tells her "he has a name" and she says "well i dont know his name" .comon you gotta be fu*king kidding me ,we have had the same 2 hour period class for about 10 months now and she dosent even know my first name ?? seriously this girl is hot but i think her IQ below 80 .... when the teacher asked "Can you tell me what a beaver is" She said "Umm i dont know" ..but she seriously didnt know she thought a beaver was a mouse. this happens with all the "cooler" people at my school ....im thinking they pretend not to remember peoples names and think they are superior to everyone else in the class.