May be it is because of the culture of Chinese, especially during the dark years in mainland China, it makes such acts so unusual and touching.
In reality, you would encounter such kindness of mankind, almost anywhere anytime, and definitely come from when you are in desperate of help. It does not have to be anything between a Man and a Woman either.
Just our past trip in New Zealand and Australia - we were being helped many times, by strangers who let us make phone calls on their cellphones, who led us a couple streets to the right bus station, who made sure we got off the train/ ferry at the right stops....
In Taihiti, a guy came back to bus station to ask if we didn't mind to share the seats with his friend and they would drive back to town - when he saw we were waiting for the Tuk Tuk 30 min after he pointed our direction ...
Such random act of kindness is everywhere. I just dont know why it has to be so sentimental, and so "Man and Woman" related. Sorry to say it, but I just want to point out there is kindness out there and we all should do our part to keep that going.