To ALL The people who are in their 20's and beyond. From Developmental Psychology studies:

The Biological CLock

Around age 20; slow, continuous changes affect workings of the body.
+ Visual acuity, hearing begin to decline in the 20's.
+ Muscle tone, and strength peak in the 20's, and decline after 30's.
+ Volume of blood pumped by the heart, and the amount of air drawn into the lungs, decrease about 1% per annum from mid 20's.

Yeah, all the great things that's already happening to me, and will continue to happen to me. Isn't this fun (all sarcasm meant).