Your lens dictates the quality of the world; focus it.
By “lens” I mean how you look at the world. Are you a negative person or a positive, optimistic person? Do you believe things can or are getting better, or worse? Speaking from experience, when you look at the world through a negative lens, it’s inevitable that you’ll see a negative world. The same applies for the company you keep. Negative people will muck up your lens and pull your energy down.
Once you understand this—not just know it, but understand it—your life will never be the same. Always be moving toward a higher state of energy and filtering out people and thoughts that pull you down.