Motivation and focus are different. Your thing sounds like motivation.
For me, it was about narrowing down my scope of "hobbies". I have tried so many things and now (approaching 40 years old) I can be more certain about which categories of things are important to me and I am more honest about how many I can juggle: family, work, fitness, and maaaaybe something else a few hours per month.
As long as I'm still playing in one of those categories, I don't worry too much about any specific project.
E.g. For fitness, I may want to try to do 40 pull-ups per day for a month. If I only last a week before I stop doing that, I am mentally okay with that AS LONG AS I am still doing something else for my fitness.