It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood; who strives valiantly; who errs, who comes short again and again, because there is no effort without error and shortcoming; but who does actually strive to do the deeds; who knows great enthusiasms, the great devotions; who spends himself in a worthy cause; who at the best knows, in the end, the triumph of high achievement, and who at the worst, if he fails, at least fails while daring greatly, so that his place shall never be with those cold and timid souls who neither know victory nor defeat. -Theodore Roosevelt
Self-sabotage occurs when we become the "critic" instead of "the man in the arena." It happens when we hedge our bets and avoid becoming too committed, too involved, and too vulnerable. We hold onto a shrunken sense of self in order to avoid the risks of "daring greatly." Continuing onward despite our failures takes an immense amount of courage and self-belief. It takes faith, discipline, and no small measure of grit, but in the end, it is the only way forward - the only way to grow and become a more complete human.
When life gets us down, the key is not to stay there. More often than not, we self-limit in order to preserve our own ego's need to be validated. When we become fixated on achievements, not the processes involved in accomplishing those goals, our ego grows stronger. So when we are derailed from those goals, our ego demands excuses for the failures. You can think of the incompetent tyrant who yells, "Off with their heads," even if he was the one at fault to begin with. The result is always more suffering and stalled progress. The ego is more interested in being right than learning how to do the right thing. When you self-sabotage you become the tyrant.
We are our own worse enemies for a variety of reasons. The most common one is a lack of self-confidence that usually begins in childhood. A plethora of parenting faux pas can result in such insecurity, but the big ones are neglect, overprotection, and abuse. For the most part, healthy and caring parents produce confident and balanced children, but even in the most well-adjusted child, some form of inner criticism will remain. This is actually a healthy part of being socially well-adjusted. It is when the inner critic gains too much control that self-sabotage occurs.
In order to safeguard our egos, which have become accustomed to some baseline level of disappointment in childhood or later in life, we adopt an attitude of nihilistic apathy. Some part of us doesn't believe our goals are reachable, and we subconsciously act in such a way that brings failure upon us. Even the smallest amount of apathy can lead to defeat, and the greater the goal, the less apathy is necessary to make this happen. The opposite scenario is also true. We can fall prey to believing that we are entitled to a certain accomplishment and actually become a little apathetic about reaching it. This can also lead to failure. Once again our egos have placed more importance on the actual outcome of our actions, rather than the execution of those actions.
The key to manifesting your desires lies in staying focused on each moment as it unfolds, and not fixating on how you think things should be. Getting back to the man in the arena, it is the quality and intention put into each effort that is of importance, not the outcome of those efforts. At the end of the game (of life), if you gave each day your best and still lose, then at least you won't have regrets. This is far better than living beneath your potential, always playing it safe, and "winning" by the standards set by your ego. Take a page from Teddy Roosevelt's life and dare greatly today and every day. You can create your own luck by choosing to prioritize learning and growth over accomplishments - stepping into the arena and out of the bleachers.