[UserNameGoesHere]

Why is this in critical thinking?

Those things described would be a geek, not a nerd. A geek has come to mean someone who has specialized interests in certain things which include any of but are not limited to comic books, video games (though as this becomes more mainstream it becomes less "geeky"), specialized card games (anything other than your "standard" playing cards), poetry, literature (other than whatever's mainstream popular), and so forth. Basically it is someone who has interests other than whatever's "mainstream popular" and which interests are looked down upon by stereotypical "jock" types and so forth.

A nerd on the other hand, is someone who is good at any of the following but again, not necessarily limited to -- mathematics, science, physics, chemistry, biology, and so forth. This would typically be your "A student" as part of the requirement is not only an interest in but skill in certain areas.

I hope this clears things up. Those are by no means all-encompassing definitions but should give an idea. Also it's possible to be both.

Edit -- Yes I realize the word "geek" originally meant a type of circus performer who bites the heads off chickens. Words can and have changed meanings (and sometimes spellings) over time. I would say the meanings I gave here are the "correct" current meanings.