Do everything with a good heart and expect nothing in return, and you will never be disappointed.
If someone does you harm, don't react, pray for them If you live a good life and practice kindness, rewards will come in unexpected forms.
But in some cases Trust me even with no expectations you still get hurt. People mistake kindness for weakness. What they fail to realize is it takes great strength to be kind in this cruel world. The more you help, and be there for people, the more depressed you become.
Your goodness and kindness will not go in vain, it may come around to you in a different way. therefore, a person with a good heart will never be disappointed.