21

21 was an internet plauge that started on vine everyone was saying 21 even when it it lost its funniness. and it was never all that funny in the first place. it was later eaten by the what are those internet plauge. several teachers claimed that the video that the joke 21 was formed around was insulting to people with disabilities because the kid who was in the video was a kid with a learning disorder and if he did not know the anwser to a question simply said "21". I can find no evidence of this online but still it may be true.

21 is proven to cause cancer diabetes and common colds also seasonal allergies.