Every now and then when I look into the mirror, I see an old guy lookin back at me. Some folks say the process of getting old is gradual. I'm not so sure of that. What about the time when a guy looses 12 - 15 pounds over night? Any ol guy readin this will know what I am talking about. You go bed and everything is normal. You look the same (pretty much) as you usually do. You wake up the next day and get dressed, but your pants are too loose. You think,"wow! that's neat. You go down to eat breakfast, and mention it to your wife. Your wife takes one look and starts to giggle, and states, "your butts gone". You say, "what", and go look into a mirror. And sure enough, your pants are loose and flat in the back where your butt used to be.
That is one of the first signs of old age. And it happens over night.