With the coronation of Aragorn as King of Gondor came the rule of men. The king married Arwen, which included noble elven names including Galadriel, who then decided to go west to the land of the undying. Bilbo, Frodo and Gandalf also went west with the elves.
The Fourth Age officially began with the departure of Lord Elrond.
I chose to wait. I wanted to study my father's notes, which I moved to my brother's kingdom.
And I decided to use my memories of Bilbo to write a book about my adventures. Only then I wanted to go west with my brother and those who wanted to leave on the last ship.
We made it a point to drink all of our supply of wine before we left because we weren't just going to leave it to some future generation.