Isn't it an amazing thing? It is stunning to watch in person as well. I once watched out trainer/farrier get into a pen with a semi-feral stud colt. The colt had been pretty terrified, as he had been raised by a semi-wild herd and only recently bought at an auction and taken to the world of barns, stalls, and pastures. Within minutes, he had him trotting, head down, being attentive to him and exhibiting mouth-licking behavior; indicating that the horse is thinking rather than reacting. The horse did have a halter on, and the trainer was able to clip a lead on and in short order had that horse obsessed with him in a good way and obedient!