I used to save all the stuff that would make a good project, but I could never finish the garage and the second story, too much stuff. Too much stuff to finish the building, and too much stuff to ever get around to doing, especially because the main project was the garage.
I would go out to reorganize a couple of times a year. Roll out all the cars and stuff, and try to consolidate. I would wind up moving stuff around, sweeping up, and rolling it all back inside. And the second floor was even worse.
Finally, I had to admit I had a decision to make. Buy lots of shelving, and turn the upstairs into a permanent storage area, organize the car parts etc, or decide to finish the second floor. I had to admit that with the massive amounts of stuff and projects, I hadn't been able to work on cars in anything but the most basic ways, and my garage was failing as a garage and as a workshop.
I decided to get rid of some projects. I found a guy who was a paid car restorer, and I sold him a boatload of car parts and a couple of restorable cars. Strangely enough, he left a ton of parts, which I came to realize were really just junk, as nobody would ever use or want them. So I scrapped them. Multiple blocks, cylinder heads, cam towers, etc,etc... all went to scrap. The rest went to the dump.
Next, I consolidated all the stuff I was not ready to get rid of into one solid, tightly packed area, not to be touched until later. Since it wasn't going to be accessed, I could really pack it tightly, and cram a lot of stuff into a small space. The stuff I had been saving to finish the second floor came to the front, and amazingly enough, I actually had an empty second floor to work on.
Well, the second floor is almost done, and I was able to use many of the windows and cabinets, etc. I had been saving. As it became clear what was being used and what would not be used, I was able to get rid of more stuff. After a while, I started to see that once the studio was finished, I could clear more of the garage of saved furniture, etc, and actually create a garage, a woodworking shop, and maybe even have the time and space to work on OTHER things again.
Hoarding towards a goal is OK - as long as the hording doesn't stop the process. Collecting projects is also OK - if you have the space to store and organize the projects and the parts. I could have easily made a commitment to go in that direction with my cars, but the truth is, even after getting rid of the projects, I still have plenty of cars to work on, and I will now have a better place to do it.
The fact that I was able to find someone who was able to take the cars on was a bonus. Sacrifice a few things now, and create the space for the projects to happen.