I've been thinking about the whole Benji thing and Bush doesn't really seem to fit. It might be about him, but here are the things that stand out to me.

Bush has a big family but they knew how old he was. Then there is the phrase, "a stray." What are strays? Out in the cold? In the cloak and dagger world there is a saying about, "coming in from the cold. Could that be the meaning of, "stray?" A spy who came in from the cold? That could apply to Bush I suppose, but again we know how old he was.

Then we have the old soul thing.

A spiritual person whom is wise beyond their years; people of strong emotional stability. Basically, someone whom has more understanding of the world around them.

Some people even believe an old soul is a person whom has learned from past incarnations, or lives. They acquired certain knowledge from their past lives and apply it to their present life… thus gaining more wisdom than the average bloke. There are other definitions of old soul but for some reason this one seems to ring truer to me.