Our society has this bias about what we should have accomplished by various stages of our lives, and that sort of bias breeds a lot of embarassment and shame amongst those who don't feel they've done enough. We also have this prejudice about older women, something that doesn't exist for older men. I feel frustration at women who continue to lie about their ages because of all this; frustration because it's such a stupid thing to lie about, and frustration because it's yet another one of those societal quirks that sets back equality and women's "liberation".
Own your age - make them take you as you are.
I feel the shame too, don't get me wrong, but I'll be fucked before I'll let that sort of age prejudice take me down.