Depression is being colourblind and constantly told how colourful the world is.
Colourblindness is a deficiency in the way we perceive colours. Depression is like colourblindness as people only see one side of the world and thinking of their own. Like colourblind people are consistently being told how colourful the world is in reality, depressed people also are told how the world is much more than their thoughts.You may look happy to others. You may laugh at jokes, dance with others, sing along to songs, but inside, you still feel sad. Internally, you still feel lifeless