I think this sentence sums it up really, "I wonder what he's up to"; like your subconscious is running through scenarios of what you might have done if things had been different. It's also a funny quirk of the mind that things you did a long time ago become clearer in your memory as you get older, so that some of your dreams that are in the past can be as real as when you were actually there. I'm not saying you are old by the way, I'm talking about memories that are older than 20 years or more - everything you ever did is in there somewhere, they'll always come back to you eventually.

It's one of the reasons I'm very fond of the Dalai Lama's proverb about always doing good things in your life, then as you get older you'll have nothing but nice things to remember and dream about.