Why do we feel the need to compete with others? If comparison is the thief of joy, aren’t you always at a disadvantage?

I ponder many things during the day and mostly in the evening. I’ve given up trying to be the other person. I can only be me. I celebrate the big and the small successes in my life. If someone treats themselves to a new car and I treat myself to a new muffin at Starbucks, does that make me a lesser person? Methinks not