Why do my friends hate me?

Okay so I always talk about how I wanna finish school and be in the canadian army or military and my friends are people who have always been there for me till lately there always getting high and I don't do drugs I really wanna get in the army badly it's all I want in life. Lately they all hate me or say they don't believe me or try to bring me down like what the fk? Any reasons why they hate me? The school I go to alredy called the army to get me in the reserve training while I finish school. Ever since they are all assholes.