that it comes down to biology and sometimes environmental factors. More often than not, men prefer morning sex and more often than not, women prefer sex at night. Basically,  there is a testosterone cycle for most men (or anyone with a penis), testosterone is at its highest in the AM. Whereas the articles indicated that for most women, there is a level of stress in the AM (thinking about the day's tasks) that isn't necessarily there at night. But as we know, this isn't a one size fits all situation.  

To answer your question though... I just like sex and they were right when they said a woman's sex drive typically increases around age 30. 😈