Susan listens quietly (although he's of course not staying still, since that's practically impossible), even when the story starts to get a little rambling and maybe off topic. He knows he doesn't really get the story, not really understanding all the context of it, but it seems like it's important to the Psionic... Even if it doesn't really sound very much like the most fun ever to him. Maybe Psi really hadn't ever done much that counted as fun?

"You didn't get a lot of time to just do whatever you wanted, then?" He knows his life is pretty different from most peoples', but honestly just sitting around doing whatever you wanted was what he did every day of his life. It's strange to think of how, to someone else, that could be one of their best memories.