Tom Hopkins from the US did some of the training. Tom had told his class about a family experience.
A few years ago I met my future mother-in-law for the first time. She was preparing a roast dinner. As she readied the lamb to go into the oven, I watched her cut off the shank and throw it in the bin. She then placed the tray in the oven. I was bewildered. I asked why she did it and the reply was "we always do that." I didn't say anything else as I didn't want to make a scene, especially as this was the first time I had met her. A year or so later, my new wife was preparing a lamb roast. Just as her mother had done previously, my wife removed the shank and disposed of it. Unable to contain myself, I asked why she had done that. “We've always done that" she replied. “But why?" I asked. “I don't know. That's what our family have always done" was her answer. Whenever we would have a lamb roast the same thing would happen. Years later we were visiting my wife's grandmother in her home where she had lived for nearly 50 years. She was preparing a lamb roast. I watched her remove the shank and throw it in the bin before placing the tray in the oven. Unable to contain myself I said “forgive me, I don't mean to be rude, but can you tell me why you did that?" "Of course I can“ she said. “This old house has only got a tiny oven and I can't fit the entire roast in with the shank still attached."Coincidentally, the very next day I was working with a group and someone said "we've always done it that way" and couldn't explain why when I asked. The 'lamb roast' story helped him reconsider his position.