I had a Dream

You'd think the way things work is: Nightmares make you wake up depressed and feeling bad for the rest of the day, and the good dreams are supposed to make you feel good. well, not with me they don't; Just today I had my best dream ever and it made me wish that I never woke up, I mean now I'm all bummed out and feeling down. Infact, I'm so angry that I could punch through a wall...(metaphorically speaking).
The thing I really don't understand is that this dream wasn't really what I'd call a best-case-scenario, not even close...