I have an answer from a different perspective than most. In life abroad, there are many people seeking to maximize their life, to get the best deals; these are bargain shoppers, but the mall of life extends well beyond the actual shopping malls, spilling into all affairs. Conversely, there are people who are simply satisfied with what they have; they don't do extensive comparative research, they simply say "Okay, this is fine." The problem can arise when these satisfiers meet maximizers, for the maximizers will say, essentially, in different expressions and sentiments, "You're an idiot!" The maximizers are correct in pointing out someone could have gotten a better deal, done more research, negotiated better, or can trade-up their romantic partner for someone more attractive or adept, but the maximizers are wrong about intelligence and satisfaction. The maximizers are most likely to find the best deals, maximize the options in their life, but lest they also be least likely to be and remain satisfied—the law of diminishing returns; but nonetheless, the thought process of the maximizers affect and can infect the minds of satisfiers.
It is natural and inevitable to compare ourselves to others, wondering or finding all the different options our life may take or possess; we are, after all, similar to other mammals, highly social creatures. There are also some built-in strategic advantages, including avoiding other people's mistakes and short-comings. Since we live in world ripe with options and each option carries additional analytical overhead, we become overburdened by the processes of decision-making and thus the strategy developed to rely on other people's judgements, thus the phenomena arose of social proof.
Think: every time you find someone proclaiming to (be trying to be) " living life to its fullest," what do you suppose prompted them.
There are positives and negatives of comparing yourselves to others, there is a fine balance to be struck between weights, but for anyone to say "Never compare yourself to anyone" is incorrect.
Pook once put it this way, paraphrased: dumb people compare themselves to dumb people, smart people compare themselves to geniuses. Dumb people, with nothing to compare against, stagnate. Smart people know they have not been leading their life as wisely or brilliantly, thus they try to improve their life. Ergo, why the dumb get dumber and the smart get smarter.