I'm trying to get concept of penis envy, but I can't...

I think it is a Western concept from feminism movement (this is my lady's opinion, she hasn't a penis envy), but it's more of masculine movement because it has nothing feminine to have penis envy.

That is what I don't understand, why does a woman want to behave like a man? She will throw away all her advantages as woman to be like a man.

???