I don't think you have to be a scientist to understand that. What it has to do with scientific creativity is what everyone wants to know. John Wheeler told me recently that I should do an experiment in which I get two groups of physicists and give one group Viagra and the other a placebo for a year, and then have a committee evaluate their scientific output during the time. He was basically joking, and I don't know if Viagra actually enhances desire or just ability. An evolutionary psychologist would say the whole point Einstein inventing general relativity was in order to get laid.
Mathematical theory is just another form of peacock feathers.
It is generally thought that Einstein's last real scientific contribution was in the 1920s, when he invented Bose-Einstein statistics. At that point he was 45 or so, so he was at the point where theoretical physicists consider their creative lives over. And, in his biography of Einstein, Abraham Pais made the point that after about 1920, Einstein, who was a very driven man, was willing to relax and enjoy life a little bit more. In some ways I don't think he would have gotten off the ground without Mileva around to bolster him and believe in him during his college years and right afterward. Einstein, however, knew he was smart.