The 12 Step Programs have incorporated the saying that, "Insanity is doing the same thing over and over, expecting different results." Perhaps failures are the result of improper planning. This could be wanting to be a physicist, but sucking at math. This could be from failing to research the requisites of the goal, playing a guitar in a rock band without lessons. It could be from failing to adequately define the goal or from not setting a deadline. It could be from not critically examining and evaluating each attempt and making the needed changes. There is probably no one reason for failure.
My failures in life can be traced to blithely assuming that things would turn out right, that I didn't have to work toward goals, that I even had to set goals. My failures were caused by a great immaturity and lack of discipline and preparation. Even when I had the opportunity to "redo" a goal, I blew it. I'm still financially affected by that decision to this day, even though it happened in 1979.
