The Boy Who Cried Wolf is a pretty good example of updating on new information, I guess.

Agreed, but the primary lesson of that story is "guard your reputation if you want to be believed." The reverse story--"don't waste your time on liars"--probably shouldn't end with there actually being a wolf, as one should not expect listeners to understand the sometimes subtle separation between good decision-making and good consequences.

But it seems sort of pointless to attempt to find old stories that show the superiority of a supposedly new way of thinking.

New stories are useful too.

I also wouldn't call rationality a new way of thinking, any more than I would call science a new way of thinking. Both are active fields of research and development. Both have transformative milestones, such that you might want to call science before X 'protoscience' instead of 'science', but only in the same way that modern science is 'protoscience' because Y hasn't happened yet.

It's also worth noting that the research and development often makes old ideas more precise. People ran empirical tests before they knew what empiricism was. Similarly, we should expect to see people acting cleverly before a systematic way to act cleverly was developed.

And if we do, what does that say about the superiority of the method (that is, that it was known N years ago but didn't take over the world)?

A meme's reproductive success and its desirability for its host can differ significantly.