A philosophy teacher is standing in front of his class. He puts a big beer keg on the table and fills the glass with a few rocks and asks his class:” Is this glass full?” They reply “Yes”.

So the teacher takes a handful of tiny stones and drops them in the glass and the tiny stones fall between the rocks into the cup and he asks: “Is the glass full now?” Again everybody is mumbling “Yes”.

Then he takes a hand full of sand and the sand goes between the rocks and the tiny stones and again he asks “Is the glass full now?” Everybody answers “yes” again.

And he explains:” Those things are all symbols for something. The glass resembles your life. The rocks are the essential things of life, like your partner, your friends, and your health. The tiny stones resemble the important things of life, like your job, your other interests. The sand resembles the extras in life, like a luxury car or a second house.

The philosophy behind it is this: You got to make sure you fill the glass that is your life with the essential things of life first, because if you fill it up with the extras – the sand – there is no room anymore for the rocks and the tiny stones.”

 While everybody in the class thinks about this in silence, one student gets up, walks over, opens a can of beer and pours the beer out over the glass, filling the empty space between the rocks, the tiny stones and the sand.

 Moral of the story: no matter how full your life is, there is always room for one more beer.