We all do this, but, because of my OCD nature, I have a real hard time with having uncompleted projects laying around, I hate loose ends!...and its why I dont have much of a stash, very few kits,.. I have a big enough problem with the unfinished projects I have now, and that is very few, without having more started and abandoned.
I started a 75mm Knight Models Green Beret Figure around September, but put it on hold so I could finish a 1/35 AFV Club kit that had been built, ready for paint around ten years ago, well that one's done, now I'm back to the Figure, I'll try to finish it off now....going to try hard and finish off every project before I buy anything new, because it just seems to be an endless cycle.
Jeff.