At first it's a lot of fun; the excitement of going new places that are far away and getting to go to interesting places like dinosaur museums and old sailing ships and that place with all the exhibits that had buttons on them that you could press to make motors run and the "Powers of 10" movie.
I was idly gazing across the back seat at the setting sun when my little brother, who was maybe three at the time, noticed what I was doing.
"Daaaad! Dan's looking out my window!" he wailed angrily.
Dad said, "It doesn't matter, Tom."
Tom said, "But he's looking out my window!"
"Tom! It doesn't matter! You can both look out the window just fine!"
I started looking somewhere else because the last thing I wanted was to get into an impossible argument with a three-year-old. Try reasoning with someone who treats the laws of logic as though they were made of Silly Putty, and who offers "Just because" as an airtight proof.
After a while I got uncomfortable the way I was sitting, and I shifted over and leaned against my door which meant I was again looking across the car.
"Dan's looking out my window!", Tom complained again.
Dad snapped, "Thomas! Be quiet!". His fuse was noticeably shorter this time.
I twisted around the other way, even though it was kind of uncomfortable.
After a while, your interest in travelling wanes. Eventually you've played as many games of Hangman and The Think-Of Game (our family special unlimited-tries version of Twenty Questions) as you can stand. Eventually you've counted as many tractors on the roadside as you've ever seen in your life, with your little brother pronouncing, "I want one of those, Mom" at each new piece of farm equipment encountered. Eventually you've taken all the naps one kid can possibly take. Eventually you've counted to 1000.
You are left sitting there bored out of your skull.
So I slyly looked over to my left, and whispered to my brother.
"...Toooo-oom!" I said.
His eyes wide with surprise and fear, he squeaked. "What?"
"I'm looooking ouuuuut your wiiiin-dooow!" I said.
Tom wailed loudly, "DAAAAAD!! DAN'S LOOKING OUT MY WINDOW!!" Dad gave up. Ignoring all rationality and common sense in favor of simple peace and quiet, he shouted, "Daniel! Stop looking out your brother's window!"