I'm 34, and I've never bothered to learn my menstrual cycle. I've never needed to try and get pregnant, and for the years I was on the pill I could easily predict when I was going to get my period. Therefore, I've never really bothered. However, I have noticed an interesting pattern developing and so I cracked open a text book (read: Wikipedia) to learn all about my cycle.
The Follicular Phase
This phase begins on the first day of menstruation, ends with ovulation and lasts roughly 14 days. During this time, heterosexual women are often attracted to men that are more feminine, with the idea being that they are more likely to stick around. Therefore, I have nicknamed this stage the Dave Matthews or Yummy Boys phase because this is when I have dreams about cuddling up by the fire with Dave Matthews while he sings to me.
The Luteal Phase
This phase begins with ovulation and ends when menstruation begins (again, roughly 14 days). It is this time that a women is most fertile. And apparently, attracted to more manly, masculine men because the extra testosterone is supposed to insure good breeding. So I have nicknamed this phase, Daniel Craig or Man Candy phase. Who wouldn't want Daniel Craig (in 007 character of course) to show up at your door and whisk you away?
Hopefully I've helped you realize a few things, or perhaps given you some ideas to explore.
Either way, it sure is entertaining.