According to Imu (chapter 1085), Nefertari D.Lily “scattered all over the world” the Poneglyphs. But how Lily was able to “scatter” those Poneglyphs in such a short time that no one was able to stop her? Thanks to the Paw-Paw Fruit.
What else is the Paw-Paw Fruit able to do?
According to Vegapunk “the power can take something intangible like pain and give it a physical form” and “you can even transfer it to others … things like imagination and memories” and – I assume – joy.
How Vegapunk enables that?
Thanks to “advance science”.
Who else had advanced science?
The Ancient Kingdom.
Specifically, Shaka says “a civilization not unlike Egghead when it comes to technology”.
IF Lily had the Paw-Paw Fruit, the Ancient Kingdom had advanced science, and they were allies, they had all they needed to store memories (and joy).
Professor Clover stated:
“Engraving this history onto unbreakable stones and scattering them all over the world … is it because they thought that if they’d written it on paper or in books, the message would have been destroyed …”
And “when they realized they were about to be defeated by the World government, they engraved all the facts onto the stones in order to pass on their ideas”.
The Ancient Kingdom had both the WILL and the TOOLS to pass their ideas to the future, to not be erased by the World government.
And what they wrote on the Poneglyphs? History. But also something else. They left four Poneglyphs with the detail to locate Laugh Tale.
Why? Isn’t their history already stored in the other Poneglyphs? What else they needed to store there to be transmitted? What Roger Pirates learnt in Laugh Tale?
“About the void century”
“The meaning of the D. name”
“The Ancient Weapons”
“That Wano had connected in the world in the past”
All of this is history and could have easily been stored in the History Poneglyphs.
But then “He laughed”.
To conclude, my best guest:
Nefertari D.Lily had the Paw-Paw Fruit, the Ancient Kingdom had advanced science, and they were allies.
They realized they were about to be defeated by the nascent world government, so they engraved all the facts onto the stones in order to pass them to the future.
But they realized they could pass something even more important. They realized they could pass joy to the future. JoyBoy’s joy.
That’s the One Piece: A tangible bubble containing all the memories – and the joy – of JoyBoy.
Theory by L7Z7Z (https://www.reddit.com/user/L7Z7Z)