If you are smacking a child to discipline them you must be doing something wrong
You were a well behaved kid with good boundries, and you're mum knew how to handle situations.
To conclude that if one resorts to smacking a child they are doing something wrong / bad parents though is a quantum leap. I have witnessed kids acting out in public, and despite their parents best efforts of telling them no, etc. and after minutes of trying to calm the situation, and quick smack solves the problem.
I was smacked as a child a few times. Looking back on it I was a brat, and I know it was a last resort for my parents. Hell sometimes I recon I deliberately pushed my parents to do it, knowing full well that they don't like doing it.