Sometimes it's not what you expect, and it's not what you want, but it's exactly what you need.
Dreams are a way for your subconscious to release any pent up worries or frustrations, and for you to visualize your goals and objectives in life. Everyone dreams, even if these subconscious movies are not remembered when you wake up. Dreams are different from nightmares because dreams are typically pleasant while nightmares are terrifying or disturbing in some way.
Sometimes it's not what you expect, and it's not what you want, but it's exactly what you need.