I wouldn't be interested in anyone my son's age either. There was a time when nosy people (usually friends & family) would tell me I needed to "find a husband" for my son's sake, and my smartass response was that I was waiting until he was grown so I could start dating his friends. lol That was a pretty effective way to shut them up.
The youngest I've dated was eight years younger, and even that was too much. Of course, it had more to do with his maturity level than anything—it didn't help that he was the baby of a family with 13 kids. lol
Younger men I encounter don't seem to care about the age difference, but I prefer men around my age.