Chances are you look your age. Statistically that's why we track age. If it didn't work at estimating then it would be a useless figure.
That said puburty-24 is definitely when skin cell turnover is the highest. And it probably peaks right at 20 years old.
After that it slows down and outer skin gets thicker and lower skin get's thinner, which produces older looking skin.
Retinoids and vit. C products can work to reverse this effect. They are some of the only scientifically demonstratable products that can actually do this.
Vit. C increases thickness of lower skin layers. Retinal decreases thickness of outer skin layers. Also, dermarollers that exfoliate have the same effect as retinol.
LED light in red can also thicken lower skin layers. This works because the longer wavelength of red light penetrates down to the dermalayer of the skin because longer wavelength light penetrates surfaces of objects more deeply than shorter wavelength light, because it is lower energy there is less potential for quantum interactions which halt the flow of the light and are defined as collisions. The skim cells in the dermalayer can convert the energy in the light directly into ATP to fuel cell production. Amd since dermacells produce collogen, red light from red led's can increase collogen production in the dermalayer of the skin.
These are the only scientific ways to look younger, besides natural genetics for longer lasting high skin cell turnover or natural genetics for high collogen production (or preservation).