Why are people like this?

Why is it that when u try to helpout someone with studies and have good intentions of just helping but instead they start getting jealous of u? Matlab bhalai ka koi zamana hi nahi hai. Even with religious stuff they say stuff like " Apka tu sahi jaraha hai" " Ap tu set ho" etc etc. Like genuinely bhai, i get good grades bcz i work hard for them. Why do people think u get things for free and as if its all luck?