My encounter with them are not good. Only in dim sum areas those grandpa and grandma is friendly and will chat with you.

Those young teens/young working adult is seriously 

Scenario:
1. Was holding the handrail in MRT, suddenly a girl behind speak loudly asking me not to touch her, I was like  I didn't even touch her though I must admit I may be swaying a bit as the MRT was fast and I don't really have firm grip. I didn't even noticed her and I was with my gf the whole time. So I speak back politely saying I'm sorry though I don't think I touched you (in Cantonese) then she replied I did and the bf beside her also supported her 

2. Was sitting in MRT and notice a bunch of teens talk. As they were quite loud (and nothing to do) so I eavesdrop their conversation and looking at their direction. A teen girl is showing off her Converse sneakers with lots of bling hence I took a glance (quite into converse too). I think she thought I'm tourist and don't understand cantonese, so she said see my sneakers so nice even that guy is also looking at mine (in Cantonese again)