Unlike being depressed, mania is a mood disorder in which people feel incredibly excited, hyperactive, and overly optimistic. Mania is also one part of bipolar disorder, also known as manic depression in which people swing from being depressed to being manic (being in a state of mania). Often times people who are manic indicated enjoying the state and getting a sense of pleasure from it since during the state they are so optimistic and energetic.
I once had an instructor in college who had periods of mania in which he insisted he was more productive than any other time in his life. However, it is common for people in a state of mania to produce things that are very poor quality or don't make sense. For example someone may write for 3 days straight during a manic state and believe they wrote the greatest thing in the world, but you would look at it and think it was garbage or didn't make sense at all (this is not always the case but it does occur).