Last night I was talking to my 25 year old nephew on the phone. He's in the National guard, served in Iraq a few years back and is now getting called up for Afghanistan. He leaves for the stateside pre-training in November and is really worried about his knees holding up when he has to carry around the 100 lb. pack.
I was trying to encourage him that while he may have inherited weak knees from his father, his auntie carried around an extra 100 lbs for 20 years and can still walk just fine.
Wow. We both were silent for a bit after that one. He always knew I was the fat aunt but had no idea the actual weight. And I was suddenly very thankful that I do still have joints that now support my active lifestyle.

But people have no idea what size translates to.