>>81624155 (OP)
That didn't used to happen in the past. You have to actively try to be stupid as you age. Wisdom is a privilege, not a right. The worst is when it happens to a parent with chronic pain or a disability, because that physical ailment gives them incentive to not exercise their mind, even though the two aren't really related. Just know that if they make a change to their routine or try a new hobby in their old age, they're not totally gone yet.