When you re-read topics in your sleep and answer them differently each time.
When you drink RC Cola, not because you like the taste, because it reminds you of Reef Central.
When your wife threatens to block RC from your web browser, as a way to get you to do something and it works!
When you quote RC every time you give someone reef advice.
When you are not sure how to answer a reef related question, you quote the RC thread number, page and number of posts down from the top, where they can find the info.