That doesn't mean I have twenty-five year-olds chasing me non-stop. I am also invisible to most men under 40. It doesn't bother me though, and I don't know why not. I know that it bothers other men my age. Part of it is that I get my validation from other things. I have a fabulous partner who loves me deeply, I'm very skilled in a challenging profession, etc., etc. In my work, I also get to spend a lot of time with cute, smart young MBAs and engineers in the tech industry, and enjoy it thoroughly, but I don't have any desire to chase after them.
Also, I've never been that interested in the very young. Most of my hires, for example are in their late 30s or early 40s.