My nephew, →[More:]
who is halfway between three and four, was at the Smithsonian with his mother a couple weeks ago, at the transportation exhibit at American History. They went to the gift shop, and he picked out his very own die-cast '30's Volkswagen.
So a week later, he was at the Smithsonian with his grandfather (they all live in the DC area, so it's a good place to meet), whom he took back to the transportation exhibit gift shop for the express purpose of looking at the empty spot on the shelf where his Volkswagen came from.