One single speech might not do it. However, a short anecdote. Several years ago, while sitting through a training on first aid and cpr on infants, I was bored out of my mind and complaining internally about how this was a waste of time, yet another rehash of common sense. When suddenly it hit me - no, this was not common sense. I had been taught these things repeatedly ever since I was twelve. I didn’t retain all of it after the first time, the second, or the third. But eventually, it was just common sense to me. I couldn’t always tell you where I learned it, or describe the textbook medical guidance. Why is it done precisely this way, who knows, but obviously this exact grip is how you hold the infant while delivering back blows.