Japanese pretend they don’t know?

I have noticed that Japanese tend to ask same questions or play they haven't heard about some story, gossip before even though they have already heard about that from some other? They just don't want to reveal that they know that...

Another question. My friend has a Japanese wife and she knows I used to live in Japan for one year, in the same city as she used before moving to my home country. But she never asks about it, how was the living in Japan, where I studied etc. Is this typical, or is she's not just interested or doesn't want to bother me?

How do you know they already know?

Why do you expect her to ask you personal questions?

A lot seems to depend on your relationships with them.

BIG disclaimer: people are individuals, and you're going to see wide variations in any culture. So what I'm talking about is where the bell curve is centered, and nothing more.

If you are telling them some story they already know they might play along as if you're telling them something new, in order 1) so that they don't appear confrontational and 2) to allow you to save face (since if you appeared to be a fool telling people things they already know you could lose face.)

Primarily it depends on the person and your relationship with them, especially for your second comment.

But there is some truth in your observation, I think. Japanese people tend to be (on average, compared to Americans) more generous in conversation. If you appear intent on telling them something they already know, they aren't likely to cut you off and tell you so. Since you seem intent on telling them something without asking them whether they know it already beforehand, they'll just let you go on. And who knows, maybe you will include details they didn't hear yet.

It's a cultural difference, and it is not them "pretending they don't know." Because you didn't clarify their knowledge before launching into your story, the fault is at least as much yours. Why should the onus be on them to interrupt you?

It's just a social grace to cause you not to lose face and maintains group unit cohesion. What are they going to say "Oh I already know that". It would be very rude for a Japanese person to do something like that. So they are going to let you tell your story.

I'm Japanese.

I have noticed that Japanese tend to ask same questions

When people ask same questions to me, I simply think (A) that they are getting old and keep forgetting things they heard, or (B) that my stories are so boring that they can't remember it, or (C) they don't listen to anybody but just try to be social.

In my case, (B) is true to a large extent. (A) is also true, because my friends are in their 50s and older. (C) is the easiest to find out. Those kind of people are always like that. But I also have friends who remember half the things I said, so at least I know that not all Japanese people are the (C) type.

play they haven't heard about some story, gossip before even though they have already heard about that from some other?

They are either the (C) type or they're one of those people like me who try not to listen to gossips.

They just don't want to reveal that they know that...

I didn't understand this part, but supposed a Mr. D tells you something but also tells you to keep it as a secret. When Mr. E comes to tell you the same story, you can't tell Mr. E that you heard the story from Mr. D.

But she never asks about it, how was the living in Japan, where I studied etc. Is this typical, or is she's not just interested or doesn't want to bother me?

Why don't you ask her about it, how was living in that town etc.? Is that typical for you, or are you not just interested or don't want to bother her?

But I'm just curious. Do you speak slowly in fewer words? If not, maybe they're having trouble catching up, especially if you are also speaking in a language foreign to you.

Sorry for mistakenly writing in bold letters at the end.

Not only Japanese. I sometimes do it too. For example, if a person came to me and told me excitedly something I know, I wouldn't tell them "I know.". and cut them off. It's so embarrassing for me as well. Maybe Japanese do that because of the same reason as mine.
I Said Maybe

Thanks for your answers! Yeah, there are differenciens in people and just wondered if this is somehow a Japanese habit to keep asking the same questions. We are around 30's so I don't believe she'd suffer from amnesia related diseases like older people do. Or maybe she doesn't remember. I have some other Japanese who might ask the same questions... perhaps they don't remember because the answer is boring to them. Or some people just want to have small talk by repeating the same questions.