How come my friend thinks he knows it all when he and I were discussing about...

[Jason]

...this type of government? So my friend were just discussing some stuff about countries who still have communist governments like China, Vietnam and North Korea. We were discussing about vietnam and talking about how different government have different ways of doing things. He told me that the Vietnamese government in vietnam denys entry to vietnam for any foreignor who disses them out openly in public. I told him that things have changed and that things are much better over there now according to a relative who lives in vietnam. I told him that if you criticize a communist countrys government like China, Vietnam and North Korea they can't do anything or deny entry because you are an american citizen. My relatives says the new way over there is you can talk about the government but you cannot protest out in public because they still punish you for that. He has no relatives in vietnam and he thinks he knows it all. We're both Vietnamese living in the united states and I'm confident that I'm more correct than him. I have had relatives who traveled back and forth to vietnam and they said things have really changed now and it's so much better now. How come my friend thinks he knows it all when I have relatives who have actually traveled there ???