The idea that meditation is like training a puppy came from Jack Kornfield, a world-renowned meditation teacher. He wrote:
"Meditation is very much like training a puppy. You put the puppy down and say, "Stay." Does the puppy listen? It gets up and it runs away. You sit the puppy back down again. "Stay." And the puppy runs away over and over again. Sometimes the puppy jumps up, runs over, and pees in the corner or makes some other mess. Our minds are much the same as the puppy, only they create even bigger messes. In training the mind, or the puppy, we have to start over and over again.
... Nothing in our culture or our schooling has taught us to steady and calm our attention. One psychologist has called us a society of attentional spastics. Finding it difficult to concentrate, many people respond by forcing their attention on their breath or mantra or prayer with tense irritation and self-judgment, or worse. Is this the way you would train a puppy? Does it really help to beat it? Concentration is never a matter of force or coercion. You simply pick up the puppy again and return to reconnect with the here and now."
- From A Path With Heart by Jack Kornfield
I quite like this idea and find it useful when trying to help others learn and practice meditation. I find it helps people be a bit kinder to themselves and also, to see their minds as something separate from themselves.
Your mind really is like a restless puppy. A puppy which doesn't want to sit still, but wants to run around and play, to explore. Sure he might sit at your feet and look at you for like two seconds tops, and then he's off. Joyfully mischievous, glancing back over his shoulder to see if you'll follow. And follow you should, patiently scooping him up and placing him back down at your feet.
Seeing your mind as a puppy is also useful in that it helps you see how fruitless it is to become angry or judgemental towards yourself. Rather, treat yourself lovingly and patiently and eventually you will notice the changes.
With regular meditation, gradually the gaps will lengthen. Gradually, almost imperceptibly, you will find your brain stays still for longer and longer. And that gap, that joyous wondrous gap, between stimulus and response, will lengthen. And you will gain control over your reactions, you will gain the power of responding rather than reacting to whatever life throws at you.
So be kind and patient with your puppy, and you will be rewarded.