Link to the picture from “Sin City” (2005) : here
Well, there might be an answer in this video found on 9gag : here
I think, as I am almost 39, is that there is three reasons about this :
1_A biological reason first. We, the men, at this age, our body change a lot. Perhaps this is what the ladies like.
2_Second, indeed, we are survivors at this age. We are dead inside because we have been too much fucked.
3_We value beauty and kindness over all. After all the shit we lived. We do not give a damn, no more, about cheap stuffs. Only the essentials matters now.
Aquila