The things I regret the most in my life took place when I was a child and was unkind to some other children. My conscience soon plagued me afterwards, but at the moment I was in the grip of my reptilian brain and was aggressive and impatient. Reflecting on this as I matured, I realized and grasped how automatic and powerful this dominating behavior was and therefore truly saw how the ego-mind works.
How could I deal with the antics of the ego-mind if I already had not fully experienced them myself? I had to have these experiences and the guilt afterwards to see how the mind plays out. It would not be enough for someone to preach to me that we need to be loving to each other. I heard that in church and from my mother all the time. But I had to go through the experience of being unloving to feel the full consequences of it and its fallout years after the fact. Then I understood the reason for being loving, because it feels better every time.
This is why I say I would not change a thing. No one can take my experiences away from me. They have led to an awakening of consciousness that would not be possible without them.