Past Imperfect

Ben: Can you take a picture of me buying the monster truck at the dentist's office? [It was given to him, but I get the notion.]

Glenn: That happened in the past. I can't take a picture of what happened in the past. I would have had to have taken a picture of it then. Does that make sense?

B: Some day I want to go there, the past.

G: The past is what happened yesterday, or when you were younger. We can't go there.

B: Some day when I'm bigger I want to go there.

After some more back and forth, it becomes clear he thinks the "past" is another word for the dentist's office.