First, I'm easily distracted. But, the real issue in working on something, for myself, that is engaging, and pushing back the "WTH are you wasting time on this for?". It's all very fleeting. It's not like I have some other burning passion to work on instead, some "if you do this you'll make lots of money instead of those toys you make thing". I don't. But, especially being older, it can be a trick at times to perseve…
I have the same problem. I see all these hackers out there making (something like) the millionth travel blog and sticking with it for years and somehow ending up making a decent income off of it. But I'm sitting here wondering if my potentially cool game idea that has never been done before is something that the world really needs, then I quit after about a week because of those thoughts. What drives people?
Of course it's possible to learn techniques and behavior patterns which can help you be a successful pure-solo creator, but it takes time and persistence (and motivation :) ) to learn and stick with those behaviors.
So my conclusion, as someone with a few dozen parked ideas (some of which got 80% near to MVP complete), is to find a partner or at least goal-buddy to help you stay motivated... and occasionally to help you remember why you're doing the thing.