Expat like to talk and sometimes complain about expats. That's one of the rules I was told when I arrived nearly 4 years ago in Cambodia. Neither me nor my wife are well connected to the Expat community. We usually have more local friends. One reason is that we actually left Germany forever, so no reason to look for western communities since we decided to live in Asia.
In this 4 years I got aware of something we call "Schwanzvergleich" in German(Google for yourself, but it is probably not safe for work). It means the kind of competition men usually do, but in that case it is gender neutral: I am talking about the "So, how long you have lived in ..... (fill your country in)?". Although it sounds like a pretty polite question, it's usually followed by 'Oh, that's not so long", and a nodding head, meaning "I understand why you struggle", if if some doesn't struggle at all.
The next level will be an answer or hint whenever you say something to an expat. "It's really sunny today". "Yes, but when we arrived 10 years ago, it was even more sunny". Or: "When we arrived there wasn't hardly any sun to find". Or: "What I would have given for a sun".
The final level is, when you start asking questions, the experienced expat cannot answer. When I arrived in small town in southern Vietnam and was asking for a vegetarian restaurant, I was told that I am now in the middle of nowhere and I have to except that this luxury of Saigon isn't available here. In fact, vegetarian restaurants are everywhere, just look for the sign. I discovered 3 within a week. The local expats didn't even know it. So this is the "Because I am here loger than you, I know more than you"-Level.
What is actually wrong. Some long time expats seems to be a bit stuck in the past. They keep telling about the past, denying any progress. ask them for new restaurants and they don't know it.
For example I observed the management of a well known coffee shop today. They were told that a popular yogurt company just opened a shop. They looked totally astonished. Like there is something they don't understand. I wonder if they even know the company.
What really counts in my opinion is what you learned in this time, including the most recent year. Asia in particular is changing every day, and it might be difficult for western people to keep the pace.
So some tips to prevent an expat virus infection: