different peopel have different opinion on good compensation

got an offer lately. A job that I like. Salary jumps to my satisfaction. Today, my friend at work tried to get some info on the compensation. I realized that his "good compensation" was way higher than what I would say "good". Are men mroe greedy than women? I read this somewhere that women are not aggressive in salary negotiation, feel embarrassed to talk about money. I am going to negotiate on relo package and feel very guilty and uncomfortable to even bring this up. and probably will not insist to get it. Are women weak species?