PAST MASTER - noun: a person who has done something many times before and has become very skilled at doing it "He's a past master at finding ways to get out of trouble." http://www.merriam-webster.com/dictionary/past%20master
noun: A person who is particularly skilled at a specified activity or art.A person who has held the position of master in an organization ‘he’s a past master at keeping his whereabouts secret’ http://www.oxforddictionaries.com/definition/english/past-master
I always thought "past master" was a gender neutral phrase applied to both men and women, and "past mistress" would refer to a past lover. I've heard "past mistress" in reference to women, though, and it had no love connotation. Has "past master" lost its "gender neutral" property? Or am I wrong and it never had any?