I can think with that, but 31 isn't exactly 'over the hill'. I was a bachelor in my early thirties, and remember courting quite a few ladies in my age group.
The problem for women is that, by 30 most of the good men are taken. Women will not be happen with a man unless he is taller than her, at least as well educated, and earning at least as much. If you are a professional careerwoman, your choices are limited.
For single men, though, 30 is a happy hunting ground. If you are tall, reasonably good looking, and have a professional career, you are all set. Yes, you can court ladies of 30, but your options extend down to ladies in their early 20s (and most of them will be single). Yes you can date women of equal professional attainment, but you have the option of dating down.
A professional man who marries a waitress who is younger, cute, and affectionate can be happy. A professional women who marries a man who is a waiter will be laughed at by her peers, and will be miserable.