There is something very human about comparing yourself to others. I think it helps us relate, and frequently find common ground.
However, there are a few instances where comparison is simply toxic to yourself and everyone around you.
Religion, sexually, and your paycheck. These things should never be compared within a casual relationship. No good can come from knowing anything about a person on these topics (unless you are in an intimate relationship with the person)
Comparing yourself to others, especially in these areas, is pointless and self destructive.
Be greatful for what you have been given in life, don't force yourself into misery worried about what others have.