It's rather sexist to be talking of 'guy brains'. These days, women have almost as many sexual partners as men over a lifetime, and almost as many married women are unfaithful. I hope that clarifies things, but it's off the point.

To take Htoad's comment, there is much more to marriage than sex, but incompatibility in sexual desire will cause major problems. There is nothing wrong with one partner, or 100 partners like me, it's just an example of how individuals are different. But is any marriage, once considered, good enough? In my view no, because I was lucky to find something very special, and something that all of my friends from my younger days did not find. Oddly, my next younger brother found a wife who was as loving and compatible to him as mine is to me, or maybe that's not so odd. Maybe he broke up with a long-term girlfriend because he felt something wasn't quite right, and then he met someone who he instantly realised was 'the one'. And for me, maybe I was committment-phobic, hence the hundred or so partners, until I met someone who I instantly realised was 'the one'. And 'the one' in more ways than sex, although our sex gets better as time passes.