In order to answer a question, I copied and pasted my own answer from another question, modifying it slightly so as to fit the fact that the question was put differently. At the same time I also voted to close the answer as a duplicate of the other question, figuring that my mostly copy-pasted answer would suffice in the meantime until others agreed with my decision to close as duplicate.
My answer was deleted by a moderator who gave me a public warning not to copy and paste answers: "especially my own".
Now, I've been a member of stackoverflow.com for a long time, and copying and pasting your own answer there is (or was) fine: encouraged, even. I've done it many times and it's always been received positively, because let's face it, there is a lot of redundancy in many questions, where the questions aren't necessarily the same, but often the same information can be re-used. And when I do it, it helps people. I've often re-cycled the same answer, changing parts of it in order to make it relevant to the different question.
Was this moderator wrong to warn me for doing this, or was I in the wrong for re-using parts of my answers?
Comments were disabled on my deleted answer so I had no right of reply to the moderator, which seemed a little unfair, especially since his telling me off seemed a bit rude (edit: he has since replied to me in a comment on the question, which is good, though I still disagree with him in principle about whether I did something wrong).
The answer in question is here. I'm not sure if other members are able to see it:
Please feel free to tell it however you feel it: if consensus is that copying parts of your own answers is wrong here, I'll be happy to accept it.
Edit: most people seem to have fixated on the fact that the question should have been marked as duplicate, rather than whether or not it was wrong for me to provide a partly copy-pasted answer from another question. I am not asking whether it should have been marked as duplicate - I did mark it as duplicate. What I was told off for was not that I did/didn't mark it as a dupe, but that I copy-pasted from my own answer.