I wish I had mustache like every other person
Well I don't have! they seem to take a lot of work. You even need special pomade called mustache wax to groom your mustache 
Oh that makes two of us but you seem to know more about it them me so tell me more
Well I don't know much more than that, but some people think that shaving itself has been around for a long time. They've found stone razors from the neolithic period
How long does a mustache grow?
I really don't know, but mustaches can be found everywhere. Even on a 4th Dynasty Egyptian statue of prince Rahotep. 
What causes the growth of mustache?
The production of hair in your hair follicles in your upper lip.