A philosophy professor stood before his class with some
items on the table in front of him. When the class began,
wordlessly he picked up a very large and empty
mayonnaise jar and proceeded to fill it with rocks, about 2
inches in diameter.
He then asked the students if the jar was full. They agreed
that it was.
So the professor then picked up a box of pebbles and
poured them into the jar. He shook the jar lightly. The
pebbles, of course, rolled into the open areas between the
rocks.
He then asked the students again if the jar was full. They
agreed it was.
The professor picked up a box of sand and poured it into
the jar. Of course, the sand filled up the remaining open
areas of the jar.
He then asked once more if the jar was full. The students
responded with a unanimous “Yes.”
“Now,” said the professor, “I want you to recognize that
this jar represents your life. The rocks are the important
things – your family, your partner, your health, your
children – things that if everything else was lost and only
they remained, your life would still be full. The pebbles
are the other things that matter – like your job, your
house, your car. The sand is everything else, the small
stuff.”
“If you put the sand into the jar first,” he continued, “there
is no room for the pebbles or the rocks. The same goes
for your life. If you spend all your time and energy on the
small stuff, you will never have room for the things that
are important to you. Pay attention to the things that are
critical to your happiness. Play with your children. Take
your partner out dancing. There will always be time to go
to work, clean the house, give a dinner party, or fix the
disposal.”
“Take care of the rocks first – the things that really
matter. Set your priorities. The rest is just sand.”

Lovely. Would love to keep this lesson close to heart.