Getting "ideal" and "perfect" mixed up is easy. However, the ideal is based on what you already know. You have a foundation upon which to construct a vision of the ideal. As you learn more, your vision of the ideal will change. This may be the result of changing values, perceptions, associations, etc. the point is that the ideal can (and will) change, eventually.
Perfect is absolute. There can be nothing better. After perfect, there is nothing.
None of us will ever be perfect. None of us will ever see perfect. We can only have an ideal and match up ur experiences against our ideal.
Sure, students can get all the answers correct on a test. The test is a measure of learning (at least it should be). The learning, however, was not perfect. Neither was the test. The score doesn't mean the student knows everything about that topic or concept. The student can't.
Learning is change. With change, your vision of the ideal changes. However, with effort, grit, resilience, determination, etc. you can find yourself, often, in a state of great satisfaction, even joy. When you reflect back on that journey, you will also see how you became better at the processes/skills needed to reach the new you.
You cannot observe perfection, but improvement is relatively easy to measure and observe.
In my eBook, The Golden Apple Manifesto, I wrote that the standard of satisfaction is not perfection. Satisfaction should come from committing to improvement, making the effort to realize your "better" self, and arriving at a point where improvement is noticeable.
I don't know perfect, but I know improvement.