Had friends in CA whose next door neighbor had a few horses. Nice animals - at one point a visiting toddler escaped supervision, went to visit the "horsies", and was found with 3 horses gently babysitting her.
We had one come and stay in our lower meadow for about 2 months. I'd be out working planting seedlings and she'd follow me around - until it started raining. Then she'd trot over and stand underneath a tree and watch me work - and they say horses have small brains!
My Dad used to say that the only thing dumber than a horse is the SOB that owned it.
A friend of mine wanted to keep a couple horses when his dad retired from farming. His Dad said, "Hell no. Never own something that eats while you are sleeping".