Quit while you're ahead
I have several sayings that I try to stick to throughout my life, and as a Mom I have taught these to my children over the years. I guess one could say that they are my guiding principles, my husband calls them this. They pretty much can be used in any situation, any circumstance, time or place. One is as the title says "Quit while you're ahead." When would this ever be a bad idea? I often hear myself saying it when we have been at the park for a good while, best to go home now. Everyone is happy, healthy and nothing bad has happened.
In training, this statement is very wise indeed. Always end on a positive which can be loosely translated to "quit while your're ahead." Had a good training session? stop. Been at the dog park for 1/2 an hour of fun? Quit. I often see dogs at the dog park who have obviously been there far too long and like small children, they are tired and cranky. Stranger had a nice greeting and visit with your pooch? Quit. Pushing it can often lead to a negative; it is always best to quit while you're ahead. Even when tossing a ball, frisbee or stick I will after a good amount of tosses say "let's quit while we are ahead." Luke tends to tweak himself when he goes after a ball. Poor ole' Tilley will sometimes stumble and hurt herself so if none of this has happened and we've had fun, quit.
Many activities or interactions can lead to negative association if they go on too long. So think about length of time and degree of enjoyment, quality is often much more preferable than quantity. And just maybe "quit while you're ahead."