THE RECIPE FOR UNHAPPINESS
You may wish to read Tal Ben-Shahar's "The Pursuit of Perfect", subtitled "How To Stop Chasing Perfection And Start Living A Richer, Happier Life". He described it as a "recipe for unhappiness", plus he helps one learn the techniques to manage this unreasonable expectation, which he was a victim of. (He is the professor at Harvard who started a Positive Psychology class with 8 students, growing the next year to 300 and the next year to 900, to be the largest class ever. See his book "Happier.")
In deed, I recall decades ago saying to my counselor "what I want to get out of this is to be perfect". She didn't even laugh. But, ah, the folly of such a goal!
ACTUALLY ITS ABOUT NO FLAWS BECAUSE...
What I actually wanted was to not make any mistakes nor have any flaws, so that I could never be criticized by others or by myself or give anybody any reason not to like or love me.
I wanted to "not fail", ever.
I didn't make it.
REALITY IS A SOLID WALL - IT WINS EVERY TIME
Perfection clashes with reality - and reality, like gravity, is not a good thing to not honor. Perfection is a set of unreasonable and unattainable standards for success. Therefore, I was guaranteed to not have success. Such an irony. Such a set up for sure failure - and unhappiness.
THE ALL OR NOTHING VIEWPOINT
I guess you could call that the standard black and white, all or nothing fallacy in goals set via distorted thinking.
It is a bit like complaining that the glass is 5% empty, as it misses the point that the other 95% is something you actually have. The other 95% is what the practice of the viewing point called Gratitude is all about - appreciating and noticing what is actually there, in actual existence, similar to the idea in the piece What You Have Versus Losses. In that piece we note that there is so much we don't see and so much we worry about not having (= losses), thereby setting ourselves up to not see how blessed we actually are. Read and completely learn the contents of The Gratitude Section!
I am so grateful now that I gradually weaned myself off of that idea of no mistakes and, then finally, I embraced Richard Lui's suggestion of using 80% as the standard for "good enough". It helped that I also learned that I could have "undesired outcomes" and still be happy, a large part of that from the nicknamed "Happiness Institute", actually The Option Institute workshops.
CRITICIZING, BLAME, AND MAKE WRONG
While perfectionism is not criticism itself, it plays right into how we blame ourselves. We need to learn to do the opposite, but first we have to learn how not to ever, ever, ever blame, as discussed in the section Criticism, Blame, Complaining, Victim, especially the piece "No-Blame - The Reasoning For" - learn that and you'll free up a lot of wasted energy and needless suffering!
PERFECTIONISM IS A SUBSET OF "NOT GOOD ENOUGH"
Allthough perfectionism is a cause of a problem, it is also a symptom of a more basic underlying cause. Most people have the core belief, although it varies, that they are "not good enough". Under that category is "not worthy" and a whole pile of others. When we solve the underlying foundation that keeps all those beliefs in place, a "miracle" happens - a bunch of dysfunctional beliefs go down the drain and no longer bug us.
The cure for the symptom of perfectionism lies not in curing perfectionism but in curing the cause of perfectionism, so you'd go ground yourself via reading the Beliefs And Thoughts section, also reading the Changing Beliefs Process.
Perfectionism, like the thought of "not good enough" has no truth in it and no usefulness only harmfulness. Change the beliefs and also remember to be compassionate and kind with yourself and to use the practice of gratitude to offset any tendency to perfectionism.
Read the piece Fear And Perfection, relating to how we equate perfection with survival and set off fear reactions constantly.
Perfect!, Tal Ben-Shahar - A "recovering perfectionist", with some great insights. He is the professor of the largest class ever at Harvard - on happiness! Read this and you'll have a great chance of letting go of this hopeless hope.