Julio, Your Mother and I Have Asked You Repeatedly to Make All Local Stops

Little brother, running up street: Look at me -- I'm the 4 train!
Older brother, running next to him: Look at me -- I'm the 6 train!
Little brother: Stop running faster than me!
Older brother: Nuh-uh.
Little brother: Dad! Julio didn't stop at 33rd Street!

--31st St, Astoria

Overheard by: five year old kids can figure this out -- why can't tourists?