I think the “secret explanation” can simply be things you don’t know (or that most people don’t know) because they’re not interesting per se, but when combined they make an interesting whole.

I enjoyed some books that don’t have anything unknown in its parts but that brought a lot of shift in perspectives for me, such as “Man’s Worldly Goods”[1] and “The Drunkard’s Walk”[2].

[1] https://www.amazon.com/Mans-Worldly-Goods-Wealth-Nations/dp/... [2] https://www.amazon.com/Drunkards-Walk-Randomness-Rules-Lives...