If at first you don't succeed, try, try again. - folk parable
We are trained to see our goal as success. We go through life thinking that we have to achieve certain things. If we succeed, good. If we don't, we should ask why we failed, and if possible, try again, pushing through again and again until we finally attain our goals. In other words, failure is not an option, or at least not a permanent one.
This week's parsha tells us a different story. Moshe explains that he wanted to enter the Land of Israel and begged G-d to let him enter the Land of Israel, but he had to accept that he could not do so. We don't hear that Moshe went on for years, days, or even hours. Instead, he asked, even forcefully, but when Hashem told him the answer was no, he accepted the decree. He moved on with his life's work, preparing the Israelites for their coming transition to a people occupying a land.
In general, we think that the mark of a successful person is to attack a problem until they reach a satisfactory resolution. Often this is true. But, sometimes, it is equally important to know when you're beaten and make peace with that. Moshe teaches us that true greatness lies not only in persistence and dogged perseverance but also in knowing your limitations and recognising the possible. However, perhaps the most important trait is not only recognising the possible but not using it as an excuse for giving up when we shouldn't. It is that delicate balance that Moshe modelled so successfully in the Torah, which we should bring into our lives.