I feel much happier when people in my social circle are well off and living a great life.
I have also found that helping those around me succeed, whether financially, or personally, usually improves my own quality of life in someway (not always of course).
I also fully agree that one should only compare self to oneself.
After all we are all unique
IMHO happiness is truly achieved when shared :)
In my personal experience, I'd say this is a very unique quality to have. Not all friends and family members can be like this.