What has surprised you so far in Phantoms?

What surprised me the most was the idea of a "phantom limb". It's really interesting how someone can still feel their amputated limb when it is no longer there. And that if you were touch somewhere else away from the "phantom limb", the patient feels as if you are touching their phantom limb AND the area that you are actually touching. This idea makes the brain even more mysterious and makes me interested in how it actually works.