"One important detail is that actions that have not yet been tried in a state s are always assumed to lead immediately to the goal with the least possible cost, namely h(s). This optimism under uncertainty encourages the agent to explore new, possibly promising paths.
- Artificial Intelligence: A Modern Approach (Russell&Norwig)
Amusing how theory can guide one's life as well as explain the inevitable disappointments. Of course, Mae West anticipated theory with "Whenever I have to choose between two evils, I always like to try the one I haven't tried before"