Impossible goal – How to get it measurable?

Thinking of an impossible goal to pick for next year, I first decided to pick the one I had put aside last year: Creating or finishing all the photo books between 2013 and 2020. Even though I would be really happy to see myself with all the finished books in my hands at the end of next year, I thought the other goal I was thinking about would probably require more of me in terms of personal growth. Maybe by working on this goal, there is a chance I could get done at least parts of the first goal I mentioned as well.

My impossible goal for 2021 then, would be something like this: Being a teacher working 75%, having free time after 9pm, having free of work weekends and vacations. My BUT is already: While being a “responsible” and “good” teacher, a “responsible” and “good” mom of 2 boys (ages 5 and 7), a wife, a daughter, a colleague and a friend. I can see that a lot depends on how I define “good” and “responsible”. There is something in it like “not at the expense of other people or my wish to take care of my children…”

1. I am struggling finding a less cumbersome title.
2. I am not sure how to make it measurable. With the books it would be obvious.
3. And what about the 25 big fails? Do I have to think of them and name them in advance or do I start working on the goal and then judge things afterwards as a fail?

Thank you for your thoughts about to set this up. I am very curious learning from you.