If you say you can't teach an old dog new tricks, what you mean that it is often difficult to get people to try new ways of doing things, especially if they have been doing something in a particular way for a long time. I think this idea comes from our experience with “training” dogs. Where we are able to get our pets to do something by repeating the task over and over again and rewarding them each time. You can train a dog to go fetch a stick, but what happens when you accid