I have a similar vice... I'm really good at planning things.

I've planned and then put together an awesome ultralight backpack, which I've used only a couple times in five years. I really enjoy tweaking it though, making it better. Turns out ultralight gear is useful for car traveling too. But I don't use it for it's intended purpose.

On the flip side, I work better from a plan. I recently spent several hours designing a crude electric guitar, writing step-by-step instructions on how to build it, then building it from those instructions. I'm almost done and the plan has kept me on track.

I have a tenancy to plan the crap out of things. Many of them I never complete; some I do.