I'd say Yes, it's when I was a kid, 8 or 9 years old, going around in a pair of shorts, shirtless, and going around to the beach, getting up early in the morning and tearing around on my Schwinn Sting-Ray, climbing trees, having crazy sand fights, etc. my body just purely natural and non-problematic. Sure I didn't have muscles like Superman or Charles Atlas which for some reason I thought was my Dad in some earlier career, but that didn't keep me from running, climbing, swimming, paddling a board, diving, pedaling my bike up "killer hill" etc just as hard and fast and exhaustingly as I could, and then on an ideal day, going to sleep exhausted and full of my Mom's horrible cooking, and dream about flying.
Puberty wrecked all that. Sure I've been athletic as hell since but that feeling of perfect naturalness is gone. It will be back the day I can go to the beach in a Speedo only and show off muscles with a lot of Latin names.