My dad gave me a butt-whipping exactly once; I don’t remember my pain, but instead his own shame at having done it. He was a good man who — in a weak, confused moment — tried out a sick cultural norm. I can only shiver at having a parent so smug that they willfully, repeatedly beat their child.
Of our three kids, we spanked one of them exactly once and, like your dad, have regretted it ever since. My mom has said several times over the years in hindsight she wished she had known about other ways of discipline
I remember my dad occasionally swatting me on the butt. But what I remember most is the time I, 10, smarted off to him and took off running. A block later, I turned and found him right on my heels. He was 50. He didn't touch me but ordered me home to my room, a first. That made a greater impression.