[Galadriel55]

I want to point out that Bilbo, though remarkably well-preserved, was quite an elderly hobbit after all. Had he been younger, and had young companions, he might have adventured some more with them. However, that wasn't the case; but even so, Bilbo picked one spot to settle down where there was most diversity of what to do and how to feel. He says himself that it's just great to do everything from eating to exploring nature in Rivendell.

Also, I'm getting rusty, so I'm not 100% sure, but did he not visit the Lonely Mountain for a time while Frodo had the Ring in the Shire? He didn't settle down completely for quite a while.