perception

according to a friend:

"just remember that the world around us, an within us, is always our own perception, and we can perceive it as good or bad. whether we see it as good or bad doesn't ever affect what it is, it only affects how we feel about it
life is what it is, and you can either be upset about it or ultimately okay with it, that doesn't change what it is, it only changes how happy you are about it."

its pretty practical, while many strange and curious discussions of "perception" exists. this is just advice, from one friend to another, about pessimism and optimism.