When Hernán Cortés first set foot onto what is known today as Mexico, one of the first things he did was drill holes into his own ships with the intentional purpose of sinking them. The Chinese did the same thing in their own foreign conquests. To most people, this appears as a foolish measure of self-sabotage; even Cortés' own men were on the brink of mutiny upon learning that their unfortunate predicament lay in the hands of their own leader. But this is simply a strategy of war. To successfully extract the precious metals they originally sought, an undeniable obstacle remained in defeating the powerful Aztec Empire, and in order to do that, Cortés needed his troops' full attention. Their complete focus.
Being soldiers on conquest in a foreign land, naturally their minds wandered astray in thoughts of their wives, their children, their lives back at home. Having those ships afloat represented the possibility to flee, to run back to what is familiar and comfortable. Cortés sunk that possibility and left them with only two options: Fight together or die together.
Sometimes I feel we can apply the same concept in our own lives. We might have an initial interest in pursuing something that is, at the same time, frightfully dangerous and magnificently glorious, but we approach it with caution. We always maintain a safety net in case we fall. While I do think it is important, at times crucial, to have an exit strategy, it's also important to investigate how much reliance we invest in that exit strategy. Do they begin harboring our excuses to retreat when we had more left to give? Do they provide enough reason to surrender the good fight in exchange for a comfortable death?
If our defense mechanisms against self-sabotage act as crutches instead of an instrument to aid us in the battle for our lives, that, ironically enough, is more of a self-sabotage than "drilling holes into your own ships" could ever be.