Over the adult years of my life, my weight has yoyo'd a couple of times between highs over 200 and lows near 150. I once figured I had gained and lost maybe 200 pounds or so as an adult.
But then I realized these weight gains and losses were not smooth; there have been ups and downs along the way, and actually I have probably gained and lost closer to 400 pounds.
"But wait. There's more."
During each day I gain and lose several pounds, depending on my diet and exercise. Those fluctuations alone mean I've probably lost and gained maybe 1000 pounds each year, over 40,000 pounds in my adult life.
It all reminds me of fractals and measurement. When measuring a coastline, the finer the measurement, the longer will be the measured length of the coastline. And similarly, when measuring weight changes the total variation will be much greater if measured every hour than it would be if measured just once a month.
Addendum: my latest weight loss success was motivated by my role in Academia Nuts, opening June 4th in the 2014 London Fringe Festival, in which I appear somewhat scantily clad in a brief scene.