Having Issue with Expectations?

Today, I came across a FB post by a long time friend about him having issue with expectations. I don't really know what he was referring to as his post was too abstractive. Well, I guess everyone has expectation towards certain things whether it is business related, relationship or family. I'd be lying if say I am someone without expectation whatsoever. I'd expect to get paid for the good service I've rendered to my client, I'd expect to have a pair of listening ears when I need someone to talk to, I'd expect to be rewarded for the good deed I have done in the past or future. All these are expectations and I believe everyone should have expectations. Without expectations, it is like riding a boat in ocean without directions. The question is at what level of expectation one should have? Having a high expectation often results in unhappiness when thing doesn't turn out the way it is planned. In contrast, would a lower expectation means closing up the door for self improvement? I am not in the position to advise but if I am asked to, my answer would be "life can be very simple, it's you to decide how you want your life to be"