What does having a bad memory say about you?

Has it ever happened to you to meet someone on the street, see them grinning in obvious excitement and not have a clue who that person might be? It has happened to me a number of times and it's quite a disturbing experience.
Once I got trapped on a subway ride, having to make small talk with someone whose face was vaguely familiar, but I couldn't remember his name or where had we met. It's a very awkward situation, as you cannot ask the person coming at you with a big smile on their face: 'Do I know you?'

I have a terrible memory and the fact that I've always been like that is kind of reassuring. At least I don't have to worry about getting Alzheimer, since I've been like this all my life.

A sign of intelligence

The question is why. Why don't I remember a person that obviously remembers me? Why don't I remember a movie everybody else remembers and I know for certain that I've seen it myself?
The idea for this post came from a study saying that forgetting unimportant stuff is actually a sign of intelligence and is good for the brain. Maybe the next time I meet someone I don't remember I could use this as an excuse.
'I'm sorry, but I'll have to ask you to refresh my memory as I don't know who you are. See, my brain has decided you were unimportant and erased you from my memory files!'
The process of deleting minor details and only remembering the big picture is supposed to help your brain work better, improving reasoning and decision-making abilities, making you more intelligent.

The introvert privilege

Another interesting theory says that introverts have a poor memory.
According to 'The Introvert Advantage' by Marti Olsen Laney, the neural pathways in introverts are longer and more complicated. That is why introverts tend to forget things or have trouble digging up memories of what was it like in 5th grade. Being an introvert myself, it was a blessing to stumble upon an Internet thread of people like me. I'm not alone in having a murky memory of parts of my life. There's nothing wrong with me if I don't remember a book I know I've read or if I find myself at the supermarket staring aimlessly at the shelves desperately trying to remember that one thing I know I went in to buy.

Things that make part of me

Before reading these theories I always attributed this somewhat annoying trait to the fact that I only care to remember important stuff. Things that matter to me, that made an impact on my life. Nothing to do with intelligence. It's more on an emotional level.
Like the guy I ran into on the subway, who turned out to be someone I used to work with. For me it was just some guy you smile to when you see him in front of the coffee-machine. A quick “hello, how are you?” and that's all. Obviously, you have no part in my life so why should I bother remembering your name. If I don't see you anymore at the coffee-machine I won't even notice the fact.
At the same time, I can still remember the phone number my best friend used to have 20 years ago. That was important because we used to talk for hours every day when we were in college and I remember her phone number because our friendship meant something.
I don't know if it's good or bad, it's just the way I am. Sometimes, I think my brain is like a very primitive computer with barely 250GB of memory, so I need to be careful what I want to store on it.
I would like to hear your comments, especially the ones that start 'Oh, I am just like you'...

Thanks for reading