Twenty years from now you will be more disappointed by the things that you…
Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.
The idea here is that regret grows more from what we leave undone than from what we try and get wrong. A failed attempt becomes a story, a lesson, or at least a closed chapter, while an untried path stays open in the imagination and keeps asking what might have happened. The nautical images make the point: a boat tied up in harbor is safe, but a boat is made to sail. The attribution to Mark Twain is widely doubted, and the words are probably a later invention, though they suit his reputation as a riverboat pilot, traveler and restless observer who distrusted timid, narrow living.
The thought also matches what psychologists have often observed, that in the long run people tend to regret their inactions more than their actions. It echoes the old adventurous strain in Romantic and Transcendentalist thinking, which values experience over comfort.
In practice, this might mean the person who has long wanted to study pottery, learn Portuguese, or move to another city finally signing up for the first class or booking the exploratory trip. The step needn't be dramatic. It only has to loosen one rope from the dock, so that a vague "someday" turns into something you have actually tried.