I don’t really expect a straight answer here but I do wonder what everyone’s thoughts are.

In China why do people expressly say they’re having fun? Like 好玩， 太好玩了，特别好玩

During a game or watching something, people - kids and adults - just say that out loud. 

Unless things have changed drastically, no one really does this in English speaking countries. It would be interesting to know if any other countries do it. You just look at peoples faces, reactions and body language to know if they’re having fun or not. You don’t need to expressly say “Good fun!” “This is great fun”. I know sometimes you do but it’s not as constant/frequent as over here. 

And asking someone if they’re having fun or something is fun doesn’t mean anything beyond asking. What I mean is, in the U.K. and I think English speaking countries, you might only ask “Are you having fun?” If you thought perhaps the person wasn’t. 

Could It have developed because, at some point, you couldn’t really “show” you were having fun? So you had to say it out loud so people would know.  I don’t really know but early Communist era Chinese seems a pretty serious place. Perhaps it goes back further ...

Thoughts?