I think you have to define, for yourself, what it means to
finish. For example, I see 2 forms of finishing here that you may want to consider:
1. If you are doing this as a learning exercise, and you find yourself quitting when you get to the point where you are no longer learning, then there is nothing wrong with that. You are indeed finishing, in a sense, because you have set your goal as, "I am going to work on this project up until the point that I am no longer learning." So, you tackle the challenges that further and expand your learning. If learning is your desired end result, then you have completed your stated goal.
On the other hand...
2. If you want to do more than learn, if you want to take your ideas to the next level and put something out there into the world that other people will benefit from and use, then this is a different form of finishing. If this is what you want to do, and you find yourself bailing when you are no longer learning, then you will need to either 1) muster up the power to finish the boring parts yourself or 2) engage someone to do them for you. If you do not have the energy to do those pieces yourself, or engage someone to do them, then you may need to evaluate if you have passion for the particular project that you are working on. I wrote about this previously [1]. On a related note, I have also written about "Doing the Work"; it might be helpful to you as you work through finding your way [2].
One of the biggest challenges in life is finishing as it is defined in point 2, above, because it involves pushing through when the going gets rough and boring, when no one believes in you but yourself, or when things are crumbling around you as you fight to not lose sight of the personal vision that you have to bring your light into the world. Lombardi said:
"And in truth, I've never known a man worth his salt who, in the long run, deep down in his heart, didn't appreciate the grind, the discipline. The difference between a successful person and others is not a lack of strength, not a lack of knowledge, but rather... a lack of will."
Wishing you the best.
[1] https://news.ycombinator.com/item?id=6122593
[2] https://news.ycombinator.com/item?id=7076143