You are right there are many with good heart.
I had same experience when i was not able to start my car one day. i tried starting two three times and was going back to my flat then one guy called me from behind and offered his help he just took his vehice to near to my car and started my car with his cable actaully i was not even noticing around me and i never found him watching me starting the car.
i was really surprised when he came forward and helped me.
I couldnt express my thanks as he was not understanding english.