Yes, but I attribute this to my unconscious mind simply using the projects to learn things. Once I get 80-90% done, over the big hurdles, my unconscious is satisfied and no longer has a desire to complete the project.
This. As long as there are still "unknowns", or things that I still need to learn/figure out, I'm good to go. But once I hit that 90-95% mark where the problems are solved and it's just grunt work, I bail out. My last project I was able to overcome this, so hoping it becomes the new norm for me.
Even though finishing/launching a project is a skill in itself, which I should learn, I fall in to this trap also.