Some of this they didn't tell you because they didn't know.
Much of it, even had they known, they would have withheld because they didn't want you to find out too soon how good sex could be.
Nearly all of it they were forbidden to disclose because the patriarchy fears the loss of male control. What if women everywhere--all women--suddenly discovered they could say no anytime to anything they did not want?
And some of it they could not bear to let you know, lest they be faced with what their own lives could have been if they themselves had known earlier.