31-years-old?
... In all seriousness, I was dating a 30-year-old last year (as a 25-year-old) and it was kind of tough. She was really thinking about starting a family and setting roots (although, as I was told "sometime down the line"), and I was in the Caribbean, plane hopping to Los Angeles, taking a train to New York, etc.
The two women I'm interested in now are within my age range, although one is a little younger. I called it off with the "choking" chick, though.