If you find yourself quitting a good project, something that you started in earnest to better yourself, consider that the enthusiasm you experienced at first must (must!) be met by a challenge of opposite and equal strength. Indeed, if your excellent idea is not challenged, it may not be that great in the first place.
Yours is a unique idea, but someone else could have had an idea like it. And they also felt the same enthusiasm.
Be reassured, though.
90% of the people who have their own (perhaps even "better") version of your idea are now wilting, and the idea is doomed to dying in the first heat.
Beware of your first challenge.