Don Norman reminds us how humans evaluate and interpret experiences before, during and after they’ve occurred:

Rosy projection: “the tendency for people to anticipate events as more favorable and positive than they describe the experience at the time of its occurrence”;

Dampening: “the tendency for people to minimize the favorability or pleasure of events they are currently experiencing”;

Rosy Retrospection: the tendency for people to remember and recollect events they experience more fondly and positively than they evaluated them to be at the time of their occurrence.”

The insights are directly applicable to design:

Design for memory. Exploit it. What is the most important part of an experience? Psychologists emphasize what they call the primacy and recency effects, with recency being the most important. In other words, what is most important? The ending. What is next most important? The start. So make sure the beginning and the end are wonderful… Accent the positive and it will overwhelm the memory for the negative.