I forget where I read this tip, but I have used it many times with great success. It starts with the notion that most women change their hair all the time. You might not notice, but a woman is very aware of these small deviations in everything from highlights to length to fluffiness. I'm probably not using the official hairdresser terms, but you get the idea. It's different every day, at least according to the woman who owns the hair. To me, hair is either brown or it isn't, and you either have some or you don't. The rest is beneath my radar.
So here's the tip. When you see a woman who you haven't seen for a few weeks, you can pay her this compliment, and it works every time. Say, "You've done something with your hair. I like it."
The woman will feel flattered that you noticed anything beyond her hair's very existence and its degree of brownness. She might even wonder if you can be her new gay friend. But she will confirm that something is indeed different and offer many details about how it got there. You can use that time to think about your hobbies.
So far, this idea isn't mine. I just forget where I stole it from. But I did add a twist to it that I will claim credit for. You know how embarrassing it is when you introduce yourself to someone you think is a stranger at a gathering and the person says, "We met a few weeks ago." This is a sure tipoff that you consider the person non-memorable. If the person is a woman, you can use the hair trick to save yourself. Simply look surprised that you have met before then pretend you are having a flash of recognition, and add "Of course! But your hair is different today. It threw me."
Now you have flipped it from being the idiot who can't remember a new person for a few weeks into a person who has such intense memory for detail that any deviation is the same as a mask.
Yes, I've used that method often. I can't say it works every time, but it sure beats my old method of arguing that I must look like some other person and I just arrived in town an hour ago.