Maybe? Sometimes? Probably not.
Pants should weigh in, he's got the knee issues. My knees sound like gravel grating but don't hurt that bad or that often. I just assume all old knees sound like that? I did have some loose cartilage or bone chips inside that floated off to some spot where it stopped barking at me. More of a wait and see than a total ignore.
Isn't the 1st Rule of Guy Health to always ignore pain stuff with a 2nd Rule being if you do Rule #1 you cannot complain about it to a spouse of significant other.
Depends on what was done to hurt the knee. Did you just wake up with it like that? If so, walk that **** off.