I got knocked down when a horse kicked me directly in the head.
Why did the horse kick you in the head?
The horse was being mean to me, and I was annoyed with its stinky shit smell.
I understand how you feel, but it's hard to predict what an animal will do so you should always pay attention when you're near them. In addition, standing behind a horse can be very dangerous, as you found out. In the future it might be best if you steer clear of horses altogether.
I don't like the shit smell. Horses are gross. Horses and asses smell.
If you think that horses are gross, then it's perfectly fine to not be near them. Keeping out of their way would be much a much safer and better option for you.