system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do long car rides take so much out of people?

Especially if they're not the one driving, why do so many people get so exhausted after a long drive? It's not like you do anything but sit there.
gpt
Cars bounce and vibrate the habitants and your body makes a lot of really small corrections to keep yourself upright in the seat. This puts a tax on your mind and body after a bit of driving. Also if you are looking out the windows for a while, it is easy to have hypnosis happen due to travelling on the highway (highway hypnosis is caused mostly at night due to no variation that the eye can see so it will cause your vision to tunnel) this can make people sleepy.