Liquorice tawses and similar unlikely entities or events automatically override that principle but I can find none of them in your account. Further, I can find a great deal which equates with my own experience. I know of a school where staff room punishments exactly as you describe were utilised by some of the staff. I also have no doubt, from my own experience, that a specific event can appear to trigger an interest in corporal punishment. I wrote about my own trigger when I first started to post on this estimable Forum. I have to say though that subsequent self analysis has convinced me that the ‘trigger’ was just a bringing to the surface of something that actually went as far back as I can remember. I think that, as you say, this is fairly common for this particular interest.