The irony about perfectionism is that ostensibly the motive behind the attitude is to do something as well as possible but worrying about doing it perfectly will make you fall short of the mark, both in terms of while you’re doing it and in terms of your ultimate development.
This is because taking risks and making mistakes are vital elements of growth, you’ve got to reach beyond yourself and your current capabilities if you want to get better. Reaching beyond yourself means sometimes falling flat on your face. Making mistakes and falling flat on your face are exactly what is anathema to the perfectionistic attitude. Any signs of failure, of coming up short, are grounds for recrimination and self-doubt. If it’s not perfect it’s not good enough, so you’re going to put checks on the very risk taking behaviors that will help you improve.
In terms of the zone of proximal development, the best way to improve at anything is to ride that edge between the difficulty of what you’re doing and your current level of ability. You want your tasks to be challenging but doable, which means succeeding sometimes but also failing sometimes. The perfectionistic attitude necessarily holds you back from that edge, keeping you within your comfort zone where you can cultivate the appearance of doing it perfectly because it’s not that hard for you. Really it’s only perfect at a lower level of development, not close to what you could eventually be capable of if you were riding your edge and pushing yourself to get better.
When we dig a little deeper, we see that perfectionism as an attitude actually holds you back from expertise, from approaching that perfection you are concerned about. From a motivational point of view, you should worry about doing the very best you can at a level that is challenging for you, not doing it perfectly at a level that is not.