He was talking about Superman, and the quote comes from his comprehensive book - Superman: The Complete History. The quote reads: "It's a bizarre story, about a strange visitor from another world, but at its heart it's a very human story too, about the dream of having power, and the hope of knowing love."
Though Daniels was talking about Superman, I believe this quote... Minus the "strange visitor" part, can be applied to most superhero (or, in our case True-Hero) characters.
The most important element is at the end: "The dream of having power, and the hope of knowing love." To me, that pretty much sums up what the best of this genre is all about.
I find it an optimistic quote because the most compelling part of the hero story can be achieved in the real world. It's about finding impossible strength in whatever you decide to do in life, and finding that amazing person to share it with.