I don't see any links to Vsauce's video on this so I'm going to assume every response is wrong. TLDR: Styles become associated with eras and people in those eras become associated with our perception of that age bracket.
Also, because of increased healthy lifestyle awareness, we are actually ageing slower than we used to. The clue is in the cigarette the top cartoon smokes. Today we smoke less, we exercise more, we use more sunscreen and we eat healthier, all allowing our bodies to produce more firm collagen in less damaged skin cells.
But what if you found out the opposite? I did it all but cigarettes in HS and college and I look 10 years younger than my middle age, it's pretty sweet.