70% done with The Wind in the Willows

What should we take away from the old sailor rat whose life is so seductive to Rat that he goes into a near trance and nearly packs up and heads out to the south seas? He obviously has that longing for adventure like the other animals, to be in another land, and he’s miserable for months after Mole keeps him from going. Should he have gone? Why stay put? Who is responsible for who here? Did Rat make a mistake? Mole?