That explains it!
(Via Not Quite Tea and Crumpets) One of them pointy headed types has had a revelation - Marriage may tame genius:

Creative genius and crime express themselves early in men but both are turned off almost like a tap if a man gets married and has children, a study says.
...
But, regardless of age, the great minds who married virtually kissed goodbye to making any further glorious additions to their CV.

Within five years of making their nuptial vows, nearly a quarter of married scientists had made their last significant contribution to history's hall of fame.

"Scientists rather quickly desist (from their careers) after their marriage, while unmarried scientists continue to make great scientific contributions later in their lives," says Dr Kanazawa.

The energy of youth and the dampening effect of marriage, he adds, are also remarkably similar among geniuses in music, painting and writing, as well as in criminal activity.

And why's that, exactly?

Dr Kanazawa suggests "a single psychological mechanism" is responsible for this: the competitive edge among young men to fight for glory and gain the attention of women.

That craving drives the all-important male hormone, testosterone.

Dr Kanazawa theorises after a man settles down, the testosterone level falls, as does his creative output.

Dang, and I thought it was the home cooking!