Always leave something to wish for otherwise you will be miserable from your very happiness.

Complete satisfaction is less stable than it sounds. Arrive at everything you wanted with nothing left on the horizon and the mind starts hunting for a problem, which is why people often feel oddly flat on getting what they worked for. Keeping something in reserve, unspent and unreached, protects the appetite. It is a practical arrangement rather than a moral one.

When you finish something large, resist filling the space immediately with more of the same. Leave one wish unfulfilled on purpose and notice how much of your energy came from wanting rather than having. Then choose the next want deliberately instead of letting one arrive by default.