Common mistakes that women make:
Mistaking romance for love.
Choosing romance over love.
Choosing current boyfriend over long time girlfriends.
Doing all the housework herself.
Hating her body, or certain parts of her body.
Letting a man manage her money.
Letting a man support her.
Not trying on clothes before buying them.
Especially not trying on bras before buying them.
Allowing herself to be guilted into situations (read: committees) for which she has no time, energy or enthusiasm.
Forgetting to remove tampon before intimate relations.
Wearing white pants during her fertile years.
Believing any claims about tampons or pads (or diapers!) being leak proof.
Not making sure that all of the sticky side of the pad is firmly secured to her panty and facing away from her tender nether regions.