What's He Trying to Say?

Harry (building a lego structure): "Mom! Look at my building!"
Me: "Very nice!"
Harry: "I'm going to live in a building like this when I'm all growed up."
Me: "Great! I can't wait to come visit you."
Harry: ?
Me: "You know, when you're big. I'll come visit you in your luxury building."
Harry: "Mom, you'll be dead by then."
Me: "Uh, I think I'll be alive for awhile when you're an adult."
Harry: "Will you look like you do now?"
Me: "Kinda. Just older."
Harry: "Then what's the point?"