Few things make me angrier than someone who ignores, disregards, or doesn't make an effort to change once they are given something to work on. What's the point in continuing doing what you're doing if it won't make you better? Why would you keep practicing with the same bad habit or wrong movement in a piece of choreography?
I don't mean from class to class, really - heck if I could remember all of the corrections I've ever been given. There's way too many things to think about, especially in ballet (head back, chin up, eyeline, fingers soft, elbow curved, arms lifted, turned out from the hips, weight over the balls of the feet, weight between your 1st and 2nd toes, hips square, shoulders back, breathing. And you haven't even moved yet) or during a dance number. But if you are given a specific correction or suggestion by a choreographer or teacher (or even friend!), why wouldn't you do it?
Sometimes it's hard to remember. I get that, I do it all the time. I'm given one correction and then the next time I do the movement, I've completely forgotten. But I remember at the end, beat myself up for it, and remember it the next time. And the time after that.
But what really gets me is when people don't care. They hear the comment, and it goes in one ear and straight out the other without hitting anything in between. It's hard for some people to change, but some people just don't want to. And why are you a dancer if you don't want to change? If you don't want to improve? Why are you still here?
If you don't give your best effort to making a correction when it's given to you, you're wasting everyone's time: your own, your choreographers'/teachers', and your classmates. You wasted a chance to improve, you wasted your choreographer's time in giving you that correction when they could have been looking at someone else who cares, and you are wasting someone else's chance to get noticed or improve.
So don't be lazy. Don't settle for good enough. Make improvements every day, and respect yourself and everyone around you by giving it your all.