Within an hour, your brain stops doing the comparative math. In a clothed environment, you are constantly scanning: Is my belly flatter than hers? Are his arms bigger than mine? In a naturist environment, the variety is so vast and the social norm of non-staring so strong, that the comparison engine stalls. Your brain literally has no baseline for "normal," so it stops trying.
Most of the nudity we see in mainstream media is sexualized, airbrushed, or surgically enhanced. This creates a distorted "norm." In a naturist environment—be it a club, a beach, or a resort—you see real bodies in all their glory. You see stretch marks, surgical scars, belly folds, cellulite, and the natural effects of aging. Within an hour, your brain stops doing the comparative math