On: A rare condition causes a doctor to experience other people's sensations

I've had this experience from time to time. I don't have this "on" all the time. This has been useful for stuff like martial arts.

It's possible to empathize with, if you have sufficient skill in concentration and visualization. You can empathize with anything.

From what I understand, we all have mirror neurons.

https://en.wikipedia.org/wiki/Mirror_neuron

So that's probably contributing to empathy in all of us.