I've noticed a couple of experienced longtime users answering questions which they surely know are duplicates of other older questions.
In at least one case the same user answered essentially the same question in much the same way - although I think their earlier answer was better and more detailed - in fact this user has answered this "same" question at least 3 times now ...
a recent question: Corrugated tracks in PCB
another recent question: What are the benefits of earthing?
and a selection of duplicates:
Why is neutral wire connected to ground at the transformer?
What are the adavantages of neutral vs. isolated grounding?
Is ground connection in home electrical system really necessary?
Is it easier to re-answer the question than it is to find the duplicates - even if you've written one or more of those duplicates yourself?
What can be done to encourage the appropriate use of SE's "duplicate system"?
Is SE's question & answer search feature so bad that it can't find duplicates?
I've asked essentially the same question over on DIY's meta , as I see the same sort of behavior over there too.