Why does he try to act so cool?

i know this guy hes the biggest douche bag ever and he tries to act so cool like in the hall ways he would like jump on my back and hop off and push me and says "Come at me!" like wth is wrong with him. hes always flexing when there isnt much and has a massive ego and would kill to be center of attention. one day he greased his hair back like an idiot. and he really doesnt have any friends at all maybe like 5 and they all talk about how much of a douche he is. it just bothers me on how someone can be this big of a tool. is he just insecure