It isn't humility, it's learning. Once you've learned something, you can no longer remember what it's like to not know it. Not fully, anyway, and certainly not

It isn't humility, it's learning. Once you've learned something, you can no longer remember what it's like to not know it. Not fully, anyway, and certainly not without deliberate effort. It takes quite a lot of mental effort to stop knowing something, and approach a task with the mindset of someone who's never known it. Good QA people should be able to do that, but it must be hard even for them.