A slight pivot but worth mentioning, I've collected a number of "children's" books that (for me) are just as good - better? - for adults. For example:

- "What do you do with a problem?" https://www.amazon.com/What-Do-You-Problem/dp/1943200009

- "What do you do with an idea?" https://www.amazon.com/What-Do-You-Idea/dp/1938298071/

- "What do you do with a chance?" https://www.amazon.com/What-Do-You-Chance/dp/1943200734/

- "I wish you more" https://www.amazon.com/Encouragement-Gifts-Uplifting-Books-G...

Of course, there are others. These are just the ones that come to mind ATM.

I've given the "What do...?" books as gifts to plenty of adult and young adults. My point is, a book doesn't have to be 200+ pages to have an impact.