My initial reaction when someone points out that I should have known something specific and didn't is to hoist a huge burden of guilt onto my own shoulders. I'll wonder why I didn't notice that glaring deficit of knowledge before committing the crime of ignorance. To aid in avoiding this situation, I keep a calendar, write myself notes (which are constantly revised), and never go to the grocery store without a list -- even if there's only three things on it. Furthermore, "I forgot," ranks right up there with "I didn't know" for reasons for self-reproach. I'm willing to bet I'm not the only one with that knee-jerk reaction.
Occasionally, I run into a horse who really fears making a mistake. They're nervous, uncertain creatures with little confidence in themselves. Working with them is extremely difficult. It's necessary not to over-face them, and essential not to punish them. If they're to become safe and reliable they have to have confidence in their surroundings and the people who work with them before they have confidence in themselves and their job. It's a long road requiring enormous amounts of patience and skill. A brief unkindness can undo months of work. Lack of consistency will make undermine trust.
Horses aren't as good at hiding their inner feelings as humans. They'll show us the effect we're having on them right away. And, to our credit, a great many of us take lessons, read, listen and watch in order to be better at working with the animals we love. I can't help but think those same efforts would be well applied to our human interactions as well. Who needs all that guilt, anyway?