The first step in sucking less, is knowing you suck

I think Linda Lovelace was the first person to put it in exactly those terms.
But the thought is not new:

When you know a thing, to hold that you know it; and when you do not know a thing, to allow that you do not know it – this is knowledge.
Confucius (551 BC – 479 BC), The Confucian Analects