What if everyone was discontent with who they were, what they were doing, and what they had? They would be continually competing for your attention and respect and constantly mired in a critical self-consciousness. They would not be happy at their jobs, so their service would be poor or insincere. Their products would be tainted with the motivation of trying to impress you or manipulate you into seeing a different image of them. They would accumulate many things that give them very fleeting pleasure and a lasting burden of upkeep and low resale value. They would defend and promote the useless things they do because they would be embarrassed if they were the only ones engaged in such futility.
What if everyone started out with the notion that they were worthwhile for no other reason than that they existed? Would they be in danger of complacency and stay in dead-end jobs or would they use the energy freed up from not trying to maintain an impression toward pushing the envelope of human achievement? Even if they did not achieve by someone's standards, would they be depressed about it? Would they need to have more and more in order to presumably alleviate the itch for more? Or would they be content with what they have and leave a lighter footprint on their environment?
People who are happy with who they are, what they do, and what they have are hard to control. Society's suicidal impulse as evidenced by the popularity of violence and Armageddon-themed movies is encouraged by the capitalist pressure to not be who you are. Even when one tells you to "be yourself", they imply that you are not being yourself right now and that maybe if you buy this product or idea you can express your unique self better.
You already are yourself. And that is fine.