Making connections

Today I had to bring Lillie to the doctor. Due to renovations in the office, they put us in this room where they were storing a bunch of medical equipment ( eye wash kit, x-ray machine, portable blood pressure monitor,etc...) Parker was pretty intrigued by everything and kept asking me questions like, "Mom, whats this do? Why is this here? Whats this for? Then he looks in the corner and notices an oxygen tank and excitedly exclaims, "Mom, LOOK! A balloon maker!!!!" ( You try explaining the difference between an oxygen tank and helium to a 3 year old.) As I tried to explain it in the simplest of terms ("It's air and it helps people breathe.") he goes," Oh, like the guy swimming in the fish tank at the aquarium!" AMAZING! How can someone who has only been living on the planet for 43 months make such connections?!?!?