In the span of the first two months of being 30, I have already:
Realized I am too old to witness a mosh pit without trying to rescue preteens as I flee;
Had enough problems with the arch of my left foot to cause my mother to conclude that I can't wear "just any old shoes you want" anymore--I may need to pay attention to things like arch support;
Recognized the sounds of a keg stand taking place somewhere near my apartment and responded disapprovingly because it was before noon.
My knee has been stiff for two weeks. I've been icing, stretching, and mumbling voodoo chants over it to no avail, so I finally decided to ask the internet for some ideas. My Google search turned up exercises for healthy senior living.
Fuck you, Google.