I have a really hard time telling faces apart that I haven't known for longer. As soon as I get used to them it's fine, but no chance to remember them after seeing them only once, or only few times.

Like a new neighbor moving in and saying: hi, I'm your new neighbor. If I see them again the next day, I can't tell if they are this new neighbor or a random person that I've never seen before. And I tried "practicing" by trying to remember the mailmen and pizza delivery guys and try to tell if they are the same, or a different person than before. But I can't do it at all.

But mostly that's not that a big problem because I don't meet new people very often. And for close friends or family it doesn't happen.

The only time when it's really annoying is watching movies or tv shows. They show the character 1 time and then expect you to know who it is. If the characters are really different then you can tell them apart by other stuff, like this is the blonde haired women, this is the old guy, this is the one with the beard and this is the person who always dresses in violet and pink. But if not, if for example there's lots of middle aged, white guys in suits, then no chance. Sometimes I stop the movie to google the characters and try to learn things to tell them apart by before continuing. But still often don't understand what's going on. And it's funny to, after watching 3 seasons of a show (and by then knowing their faces) to rewatch the first episodes and suddenly understand what was even happening.