If you could climb into your head

Tonight Zeke was asking me about why some big trucks have bunks above their cabs. I explained that it was so the drivers could sleep if they were taking long trips. He then wanted to know how the trucks kept driving while their drivers slept. I explained that they didn't. He was, it seems, thinking about the image of a driver climbing up into a bunk above the cab of his truck and looking out those little windows. He thought for a minute and then remarked:

Daddy -- wouldn't it be funny if there was a window in your head, and you could climb up into your head and look out the window? And then your head would be bouncing around with you in it.