Health, Happiness, and Jack Lalanne

I was on a flight last week from warm, sunny Phoenix to the wind and cold of Chicago. It was late at night, and there were delays as we waited for a gate in Chicago due to the de-icing of planes waiting to take off. Faced with the wait beyond our control, it was fascinating to see how some people were jovial and laughing while others, tired and miserable, were barely able to smile as they sank into (and for some, overflowed out of) their seats on the plane or in the lounge. 
Let's face it, we are all busy and it takes energy every day just to keep going, smile or have patience. And, it seems, some people have more of the energy resource than others. I think Jack Lalanne was on to something...