That's one of my favorite line. Its not that I'm so negative in my life but It is much better to expect nothing in return so you would never have a disappointment whenever there is a failure or a bad outcome.
"Too Much Expectations Leads to Sadness"
Totally agree with this. There was a time I was expecting too much. In the end it gave me a bitterness and sorrow in my life.
"Act Without Expectation"
That's the very least we can do in our life to improve ourselves and to be satisfied to the outcome but don't stop to aim high or reach your goal. Just stop expecting too much.