When I was in fifth grade I was one of the fastest kids on the playground. My spindly, aerodynamic frame provided agility and quickness rivaled by only a select few of my peers - one of which was a kid named Joey. Joey was a short kid but built like a damned jackrabbit. He'd sprint around the playground on his little legs like a demon dancing on fire. I, on the other hand, lacked in any respectable muscle form whatsoever, and owed my speed to the fact that I was built like a toothpick with really long legs.
When Joey and I weren't racing around the school yard with other kids, we'd sit under a pine tree and talk serious about our techniques for being fast - what kind of face to make, proper hand posture, what kind of shoes to ask your mom to buy. Important stuff. The manner in which we spoke about running could have been compared to the thoughtful pontifications of ancient, Greek philosophers.
"I proposeth that the fastest shoes are Nike's Pumps. The extra air maketh thou lighter and, thus, quicker."
"False! Pumas are infused with the spirits of actual pumas. My dad saith so! Running in them wouldst, of certainty, make you impossible to catch!"
I look back now in awe at how easy it was to sprint to full speed, cut maniacally back and forth and stop on a dime. All without even a tinge of joint or muscle pain. In the spirit of learning from one's past, I guess that memory serves now as a cautionary inspiration to keep myself active, lest I find myself, in my geriatric years, reflecting on the days when I could walk up and down the stairs "without even a hint of hip pain, and nary a pause." :)
P.S. The best wise men are those who share their wisdom, so here it is.