Why does my coat grow so speedy?

I am 17. and my hair grows relatively quick. when i get a style at the same time as my friend, i hold a shag in no time...while his fuzz remains short. why is this? am i eating more natural than him? or just consuming more of a abiding type of vitamin? i guess a better question is: what factor determine the speed of hair growth?Why does my coat grow so speedy?
inheritance, weather (hair grows faster in summer than winter), the amount of keratin surrounded by your body, a diet rich in Vitamins A, B-Complex, C, D, E and iron, calcium will variety hair and nail grow faster and healthier. Many factor.
Family Genetics might have something to do next to it.
I am assuming you are a male. If so, the answer is testorone! At 17, your hormones are flaring.