Generally yoga is considered non-competitive. Generally. There are asana competitions and there's many peoples tendency to eyeball the best person in yoga class wanting to have the ability to hold a textbook Utkatasana for minutes without a sweat. Humans compete - it's built into our genetics and instincts. If we weren't competitive the human race would've died out instead of the neanderthals. Competition is handy when it decides who lives and who dies. Its even helpful when you're trying to achieve a goal and you need something to help you do better today than 2 months ago. Competition drives progress.
However, sometimes that competitive outlook can weigh you down if you're not on top. If you're doing worse today than yesterday, or six weeks ago, or four years ago - your natural drive to want to be better than you think you were then is going to irritate and discourage you. It happens, but don't let it get you down. Just because you sat in painless meditation for 45 minutes yesterday doesn't mean you have to do it again today. Five minutes is just fine.
Let yourself be where you are today. Sometimes you need to compete with yourself on your ability to accept things as they currently are.
