Why is he stalking me

So today I was walking home I seen him and he hid behind a car and followed me down the street then this morning he followed me and my family with his freinds he even got a taxi from his freinds house after he started an argument with me because I told him I was going to speak to his mam but I never and he showed up at his mams house with his freinds thinking I would be there if he sees me in the streets he starts shouting things to get my attention he tried to get his freinds to follow me home on a bike before and new sort off where I lived but I hid so they didn’t know where I was going he’s 16 why is he stalking and harassing me if he says he hates me