The Halfling-Dragon Principle states as follows:

If you find yourself in the company of a halfling and an ill-tempered dragon, remember that you do not have to outrun the dragon; you simply have to outrun the halfling.
This statement, with roots in the Dungeons and Dragons world, signifies an acceptance of mediocrity.

A little background, for those who are not familiar with the rules of Dungeons and Dragons:

  1. Dragons can, even on a bad day, move faster than most humanoid characters.
  2. Halflings are, as their name implies, about half the height of the average human, so they tend to move a bit slower than humans (by Third Edition rules, 2/3 the speed).
  3. Dragons, when in a rage, are often known for devouring the first living thing they can catch. Sometimes, I don't understand why this is true (other than lazy DMs), as dragons are generally renowned for amazingly high intelligence.
  4. Since a halfling generally has a high Dexterity score, it will often take at least 5 rounds (approximately 30 seconds) even for a dragon to take out a halfling, by which time most intelligent players can get far enough away from the dragon to make a getaway.
Therefore, if you can outrun the halfling, you can generally escape the dragon.

By this principle, excellence is not necessary. You don't have to try to outrun the figurative dragon (reach for the stars, as it were). You simply have to do well enough not to get chomped (failure). However, as a cautionary note, beware of setting your sights too low, because halflings can often surprise you (something that Gandalf and Sauron have often discovered).