If the goal cannot be achieved, there is only one possibility - that one's own abilities are not yet sufficient. If you feel capable but still haven't achieved your goal. There is only one possibility, it's just that you think you can do it, but in fact you can't.【learn English】

行有不得，反求诸己。

如果达不到目标，只有一种可能，自己能力还不行。如果觉得自己能力行，但还是没达到目标。那只有一种可能，只是你觉得自己行，其实并不行。