These new knees that we have are much like a new toy that we had when we were younger.
For a while, all our attention is focused on this new spectacle, and we wonder about it and if it is working correctly---as it should.
Later on, when all of the gloss has long worn off, and the toy or the bike or the "whatever" is still working, we just take it for granted. We no longer notice the little issues.
The reason that we no longer notice it is that it is normal. Normal is good---normal is what we expect.
Your new knee or knees is much like this---we fuss over it (or them), we worry greatly about it or them, and we focus our attention on them---"Is everything OK?"
I can tell you that I am going eight years now, and I can go for days without thinking about the fact that my knees are 53 years younger than me. I can go for days without thinking about my knees, period.
That is because they are normal---they do what they are normally expected to do, and I just focus my attention on other more important things in my life---like what I am going to have for breakfast or how many miles will I ride---or do I need a haircut?
The idea is that we have focused our attention on our knees for so long---first, they were bad, now they are new----that we have to understand that normal is something that we crave---and normal means no worries.