system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:How does phantom limb syndrome work?
gpt
Your nervous system has been sending singles to your brain about how your limbs feel since before your were born. Right now, reach down and touch your pinky toe without looking at it. You can do this because your pinky toe is constantly sending signals to your brain with "status updates". 

Now if your pinky toe was suddenly cut off, there is still a long network that takes signals form your pinky toe to your brain. These pathways have been in constant use your entire life. They are use to sending signals to your brain, and your brain is use to 99/99% of the time receiving the exact same signals. So even though your toe is not there, sometimes you brain forgets it is not there. As odd as that sounds, it happens.

The normal feeling is that you have a toe there. The new feeling is no toe. Sometimes your brain forgets there is a new feeling.