When she told me... no seriously I don't know. For a guy I think it has more to do with where you are as an individual. I waited to get married because I realized that as a youth I was too wild and stupid (in the moment) and like anything else worth keeping I would have screwed it up. I was traveling the world and was determined to stay single although a few tried to get a ring on me. Once I got older it became more of a rational decision. We, too, have biological clocks. I didn't want newborns in my 50s! Then I met this girl, 12 yrs. my junior, beautiful, smarter than me (almost), funny as shit, and full of direction. And I just knew. We spent three years together before getting engaged. It was just the right fit. 10 years, 2 kids and going strong. There - hows that?