I was thinking, in part, about the call of the sea when he mentioned to Dawn, at Aragorn's coronation, that he knew what it was to be homesick. He is going to spend many years being home sick first for Mirkwood, then for the sea. I can see that, when he finally sails, he will again be homesick for Eryn Lasgalen, Ithilien, and his father.

He gained much on the quest - but lost some of his peace of mind. Which is also part of growing up, I guess.