Even if I know my chances of success are slim because I've been disorganised, have missed deadlines, have generally not followed my own rules for getting stuff done, or didn't really know what I was doing anyway, I'll still press ahead and try to get a project done.

If my deadline for a project is tomorrow, and it's not looking likely.  I'm still going to push ahead until tomorrow, until the time of the deadline, because it isn't over until I've tried every possible avenue, every possible scenario, pivoted every single bit, and generally done all I can, before the clock announces I've run out of time.

I've done this with large projects, small projects and various other commitments.

I do it because to me, not completing is failure.  But pushing forward and doing it anyway, is success.  Doing is success because it let's me complete things with integrity - knowing that even if I've failed, I've failed while giving my all.  Which makes me feel better than any other kind of failure, because then I get to experience a failure fully and learn.

The achievement is in doing the actions to attain the result, and learning what is required in order to attain a better result the next time.