But Bilbo sometimes outright lied or withheld the truth in his "tall tales." And even when he told the truth, the whole truth, and nothing but the truth at the Council of Elrond, Merry and Pippin were not present. And in both The Hobbit and Fellowship, Bilbo was extremely secretive about the ring throughout his life, so I'd venture he remained secretive about the ring. I also wouldn't put it past the ring's influence to feed that.
And then we come to the whole thing about how in the world did Pippin know to use that specific Gollum tease on Grishnakh? It felt too calculated to be a simple hail Mary/shot in the dark, especially given Grishnakh's reaction that he seemed aware of Gollum and precious.
I don't know... that whole interaction just doesn't sit right with me. Everything around it feels too coincidental. How would Pippin innately have that innate, very specific understanding of how to say "gollum, gollum, precious" and act as Gollum would? Would Bilbo's tall tales and books written mention all those details, especially given how secretive he was about the ring and how he admitted that the book wasn't the truth? And Merry and Pippin strike the others as kinda flighty and not people you'd make privy to the most pertinent information. Maybe (and that's a BIG maybe) I'll buy that maybe Merry and Pippin badgered Samwise to tell them everything he heard at the council of Elrond, but I'm sure there are details he may not have picked up on, since whenever multiple people are exposed to something we all naturally attune to different details.
Anyway, I'm still in the middle of the Treebeard chapter and it's a good one.