That's an interesting question.
It does sometimes, if the expectation isn't met. However, there are also times when expectations hurt more then the result.
Ultimately, I think it's a good idea to create positive expectations. Regardless of whether it pays off or not, it's better to enter a situation believing something good will come out of it. That increases the odds of something good happening.
It's a great feeling when an expectation is met or even better - surpassed.
If an expectation is unmet, depending on the situation - maybe that's a positive too in it's own way. I know, I've entered a writing contest expecting to win. But didn't. Was I upset? A little bit, at first. However, that quickly passed. I got some good feedback from that contest. I started working on my manuscript again to improve it. I think it was for the best. I'm planning to win next time.
So, I guess it mostly depends on attitude. How you view expectations and the results.