system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why can't I swallow twice in quick succession, without it being difficult?
gpt
It's because swallowing starts a chain reaction of muscle movements in the throat all the way down the digestive tract called peristalsis.  So the top muscles in the throat have to wait until the adjacent muscles are ready to start again.  It's like trying to start a "wave" at a sporting event when the person next to you is still standing up.  It just doesnt work.