The quote by Paul Ketz says, that who thinks themselves not being capable of changing the world, underestimates thereselves.
I realized a long time ago, how my surroundings affect me in some matter, if I want to, or not. The logic conclusion is, that I have an influence on everything around me, as well. Being self-important is not good, but the opposite makes people unnecessarily tiny. I am firmly of the view that if I do something positive, people around me perceives it – maybe unconsciously – and maybe copy my behaving. Best example: When I order a meal without meat, people close to me rather eat something vegetarian, too than they'd do with somebody who consumes loads of meat.