Negative comparison is one of the eight thinking errors of people with low self-confidence. Immediately say “stop” when you compare and replace that negative thought with something positive that is separate from the situation. If you do compare yourself with someone else, let that person inspire you. Yes negative comparison is a thinking error. I am petrified of heights. It doesn't bother me on an airplane, but put me on a roof top and forget it. When I was in the army we were doing war games and we were required to repel down the French Alps to our target. I was dead set against it until my sergeant said, hey the enemy is fifteen minutes behind us. I was on the rope and ready to go. Unfortunately my belay man paniced and pulled the rope too soon and I ended up crashing into the side of the mountain and had to be rescued.