This bag of bones, so lithe and lovely now, will become your burden to bear. This flesh, this fat, these folds. The wrinkles in your forehead, the creases in the corners of your eyes. Gravity gently exerting its force on earlobes, buttocks, breasts.
Impossible as it is to imagine, you will experience the body's revolt. Cysts and tumors, blood clots, weak knees and stiff joints. Kidney stones and cancer. The thousand natural shocks that flesh is heir to.
I know you don't believe it, but trust me when I assure you that you will grow old. (You are ugly already, despite your shapely thighs and high breasts, your firm skin and taut stomach, your perfect selfie smile.)
So the next time you remark flippantly on someone else's bag of bones, the next time you make someone feel insignificant and small for the burden they bear as a being of bone and blood and flesh, you would be wise to remember that any body can go at any time. A weakened blood vessel in the brain will do it, or a blocked artery. A peanut butter sandwich or an oyster or a bee sting. Something you can't see, can't predict, latently lying in wait. A hammer to the skull, perhaps.