Perhaps, but all that’s mentioned is age.

I’ve heard knees-crap-out-after-30-amirite jokes since my early 20s. It’s a form of denial coalition-building favored by folks obviously avoiding important lifestyle changes, and it’s rarely harmless to affirm that kind of denial.

In addition, unexplained joint pain is a symptom of a number of chronic illnesses that have better outcomes with early diagnosis and treatment, such as rheumatoid arthritis. If someone thinks it’s normal, they might not even ask about it until the pain and damage is life-altering.

That’s why I say it shouldn’t be treated as normal.