Good uncertainty

Anything can be boring.

In an important way, success is only success because of the possibility of failure. Winning a prize means nothing if you cannot lose. Discovery, progress, and health are so wonderful in large part because we understand and have seen the lack of each. Anything can be taken for granted.

Eliezer writes,

What we need to maintain our interest in life, is a justified expectation of pleasant surprises.

The hardest part about that goal is that expectations are justified only by experience, so that if your life has had few pleasant surprises so far, it's hard to perceive the world that way. However, for those whose lives have had substantial pleasant surprises mixed in with the normal trials of life, this expectation seems rather reasonable.

The key, however, is the uncertainty. If the events weren't surprises, they would still probably be pleasant (though perhaps impatience would diminish or eliminate the benefit), but not quite the same.

That's why taking risks is so important. Without them, we can and will see only small changes in our happiness over time. The spikes of unexpected success--particularly when contrasted with the troughs of temporary failure--constitute a memorable life.