I start projects frequently.
Some even come close to completion, although they are seldom ever really completed. I also tend to have more than one going at any one time, although the last few years I have tried to limit that.
Most of them are not photographic in nature though.
Currently I am busy building an off-road camping trailer. This one has a deadline: it needs to be ready for an (already booked) family camping holiday to Namibia in April next year. Part of this will be a large 4-person roof-top tent I started making a few years ago, and although we have used it a number of times, it is still not quite finished.
My only photographic project to date does not have a deadline though: collecting photos of Southern African bird species. I have been busy for about three years, and currently have around 250 species (out of a possible 1000), so quite a long way to go though.