Some people in Lebanon find pride in pretending that they do not remember your name. They think that by doing that they project an image of themselves as important and busy people. The most annoying among them are those who tell you "remind me of your name?" "of yes, yes, we met yesterday!!!". And you would be sure that when you met only "yesterday", that person had asked you all kinds of personal questions about you let alone where your name comes from and had listed all the people they know with that name (because they know a lot of people of course). Yesterday, I witnessed a conversation where a guy told another "of course, I know you, you are XX, my friend always talks about you!" I find out later on that the guy is gay. I don't want to stereotype, but I specifically asked if he was gay because of this not so common behavior among straight men in Lebanon. (Not to say that this behavior cannot be found equally among Lebanese gays).
Now there is this other category of people with whom you might have had long conversations or had coffee with let's say not so long ago or had an unforgettable fight with, or seen a million times, and then one day they pass by, throw a glance at you, a glance of "I know you", then lower their eyes and go by without even a smile. I do understand that in some of these situations, one or each of the two people would be wondering if the other had recognized them, but in most cases, it is this recognition that they find hard to admit.
So this pretentious Lebanese knows a lot of people, you included, and behaves the same with all of them. When they find themselves in a crowd but unaccompanied, you find them restlessly looking for familiar faces, and then they spot you and they run towards you, with "don't you remember me? we met yesterday". Of course you remember them but then you would say "remind me of your name!!!"