In my opinion, expectations are of two kinds
A. Expectations from People are one of the biggest reasons for misery and unnecessary suffering. Our social life is so complex that we end up hurting people even if we don't want to. Our Ego and Assumptions sometimes hurt people more than the actual event.
So when it comes to people, keep your expectations to zero. period.
B. Expectations from Dreams and goals should be infinite. Dream the biggest dream and plan the biggest goal, the only limit is your mind. In this type, you are only limited by your imagination. As they say, shoot for the moon and even if you fail you will land among the stars.
Albert Einstein (The greatest physicist of all time once said)
"If you want to live a happy life, tie it to a goal, not to people or things."