I like Thunder Bow's point that after the crash, you become more grounded. I would just add that it's a painful experience. So if this is talking about your crush, perhaps the dream is saying that, although it's painful to have your mood crash when you realize he is with his girlfriend, it's truly the most grounded (realistic) perception. Perhaps it is saying you are most grounded when you can stay with the idea that it's not going to work.