So on our way to the Seattle Art Museum today, Isaac was unusually silent throughout the ride. When I had a chance to look back to check if he had passed out, there he was just looking out the window, in his shades, and contemplating who knows what in silence.
I said, "Isaac, you look really cool!" and gave him a thumb's up.
To which he replied with a smile, and reciprocal thumb's up. :)
Nice.