Your story spontaneously reminded me of the book "Snow Child" by Nicolas Vanier. I laughed a lot about terrible horses and enjoyed the humor the author sprayed.

Self-confidence is certainly a key to maturing into a human being who respects all living beings. I very much see that the way you do.

Though some further thoughts: Having trust would be a pointless undertaking if it were not disappointed in good time. Disappointment is not something that can be chalked up to someone else, only something that you didn't see yourself and then began to see from a certain point in time. The point is, it's easy to trust people who are friendly to other living beings because they have already achieved something that other people have not yet achieved. The hard cases deserve our trust all the more because they can obviously be observed being unfriendly to other living beings. But this unfriendliness is not manifest and is only an excerpt of what you see of them at the moment when you catch them being negligent. As long as you yourself can do without people spontaneously trusting you because they observed you in a weak moment when you were unfriendly to other living beings, the world is fine. But if you like to have the confidence of people who experience you with a weakness and who say of you that they remain polite to you, but don't trust you a metre over the way, they fix the image of you as manifest.

It would only be manifest if a person were permanently, durably and consistently unfriendly to all living beings. Such a person is probably very rare, because there are always people or living beings in his life who receive his kindness. Besides, we cannot know that exactly. Someone may tend to be an unfriendly person, probably because he himself believes that the world is populated by rather unfriendly people.

You probably wouldn't find it entirely fair to be classified by someone's gut feeling as "not trustworthy per se" just because you have just had a moment of weakness. I agree with the gut feeling in that it perceives something momentary in space-time, but it doesn't have to be true per se (neither the past nor the future).

That which you turn away from has decided that it is not trustworthy, is more likely the self-recognizing. An uneasiness that reminds you of what it feels like to have been unfriendly, mean or hurtful to other living beings.

The healing is found in trusting someone who is clumsy and unfriendly, and by experiencing it, he can learn to be trusted despite his weaknesses. Healing, on the other hand, is not so urgent for those who are already friendly to all living beings. They have already achieved what most of us have not.