While Buddhists are undoubtedly correct that suffering is caused by reality not meeting our expectations, their solution is problematic. Many times our expectations re-shape reality so that they are met and we are happy. If we stop having expectations and accept reality just as it is we miss out on all those opportunities.
I think the idea is that even if you are able to restructure reality to fit your expectations, it is only a temporary fix and your happiness is short lived. Also, you don't need "expectations" in order to reshape reality. In fact, I think the less expectations, the better you are prepared to reshape reality.
Great perspective. I do feel like it's a bit of a slippery slope though. One should be proactive in life, and not just let things happen to you all the time. But when things are out of your control, you can choose how to react to them. Very helpful reminder.