We can always look over the fence and see how our colleagues and contemporaries are doing. Sometimes business acquaintances or former work colleagues are making shed-loads of money; much more than we are. I know people who get very jealous and ask why those other people should have more than they do.
The answer is always because those very successful people have worked very hard. They may have had a bit of luck, but luck does not help without hard work.
More to the point, can we learn from the success of others? What have they got right and should we try the same tactics?
Also, if we are happy with our lives and financially comfortable, why envy others who have more money. Are they happy too?
We can always learn from our peers and we should, but envy is one of the seven deadly sins and it can gnaw away at our confidence.
Work hard, be happy, and feel better without comparing our lives to those of others.