Most horses would remember a chap who turned up with treats on a regular basis.
I already liked Viggo Mortenson, but when I found out he buys the horses he works with and keeps them for himself, well, it became clear that he is in fact the perfect man.
That was a lovely thing to do ðŸŽHe even buys horses for other people! Arwen's stunt double really fell for Arwen's horse in LotR, but couldn't afford to buy it. So Viggo bought it for her.
Back in the days of Westerns, particularly in the 50s and 60s, it wasn't uncommon for the stars to always ride the same horse in different films. Some also bought their horses afterwards, or used their own horses from the outset. John Wayne is an example. Also Roy Rogers with Trigger. In Bonanza, the horse ridden by Lorne Green, had also been used by James Arness in Gunsmoke. When Bonanza finished, Lorne was worried about the future of the animal, who must have been getting on a bit by then, so bought him and put him on permanent loan to a local riding school for the disadvantaged so that he could see out his days with a safe job. It obviously suited him because he lived into his 40s.