“It means the depression that arises from comparing the world as it is to a hypothetical, idealized world.” ~The Big Bang Theory, Season 3 Episode 11, “The Maternal Congruence”
Learn to accept things as they truly are. Never succumb to wasteful depression, wishing for something that isn’t. Do not be dismayed by how things ought to be. Take what is; accept it. Approach the true circumstances with open minded optimism and then endeavor to better them.