A vet tells of visiting a home to euthanase an old family dog. The parents wanted their 6 year-old son to be present. The boy seemed to take it all very calmly. Afterwards, the adults were musing on how animals don't live as long as people, and the boy piped up, "I know why." They asked him to explain and he said, "Well, we have to learn how to live a good life, don't we? Dogs already know how to do that, so they don't have to stay as long."
The story goes on to give tips for living a good life:
if a dog was the teacher you would learn things like:
When loved ones come home, always run to greet them.
Never pass up the opportunity to go for a joyride.
Allow the experience of fresh air and the wind in your face to be pure ecstasy.
Take naps.
Stretch before rising.
Run, romp, and play daily.
Thrive on attention and let people touch you.
Avoid biting when a simple growl will do.
On warm days, stop to lie on your back on the grass.
On hot days, drink lots of water and lie under a shady tree.
When you're happy, dance around and wag your entire body.
Delight in the simple joy of a long walk.
Be loyal.
Never pretend to be something you're not.
If what you want lies buried, dig until you find it.
When someone is having a bad day, be silent, sit close by, and nuzzle them gently.