Don't let the title mislead you... it's not the caretaker/owner, it's the horse!
Is it just me or do some horses just not like the brushing/grooming aspect of care? I mean, my mare just doesn't seem to like it. I have had her over a year now, and she still will nip at the lead if she is tied or swish her tail and seems generally annoyed with the fact I am brushing her, or at least the start of it. After a while, she starts the yawning or whatever and stands quiet, but I am not sure why she wouldn't like being brushed? I thought all horses like being brushed!
I thought it was excitement and preparing herself to be trained/raced as she was a racehorse... But I don't train/ride her every day that I brush her and a year off, I thought she would have figured it out by now lol
I thought I was being too rough with the brush (it's a gentle bristled brush to begin with), so I went gentle... same response.
Maybe it is her way of enjoying it, I don't know.