It's difficult to understand what someone with a mental illness experiences, but this exercise may give you a better idea. Now put three or more of these items together. Say you hadn't slept for three days, you heard the same music going on and in your head, and you couldn't find your car keys.
Nothing seems enjoyable or fun anymore.
Even your favorite activities, spending time with friends, listening to music, or going to the theater, no longer give you any satisfaction or pleasure. You suddenly find it difficult or impossible to remember anything you read. You can't remember anything your boss or teacher says in class. You sit through class or a meeting really trying to pay attention, but when it is over you can't remember what was discussed. You live in a black and white and gray world, because all the color had faded away.