Through perseverance many people win success out of what seemed destined to be certain failure.

Certainty about how something will turn out is nearly always a forecast dressed as a fact. Situations that look settled contain variables nobody has counted, and one of them is how long a person is willing to stay in it. Plenty of things that were going to fail simply did not, because somebody kept adjusting past the point where the outcome seemed decided.

If a project of yours has been written off, including by you, check whether the verdict came from evidence or from fatigue. Those two feel identical and call for completely different responses.