How do we stay positive ?

Staying positive is very hard, you have to have a mindset were nothing bothers you. You have to just let things roll off your back even when you just wanna tell that person off. How do we stay positive in such a negative world? Well I came up with this stop putting things into your mind that's not beneficial to your happiness and goals. We must benefit from positive information and be able to take that information and use it or become something or invent something or just store that info.