Let's spell it out for you.

1) "Yes, Roger, if you posted to one of those general brawl threads or Spam threads that was deleted, then your message was deleted along with it. That happened with a number of Martin Gibson threads, because it was impossible to separate the wheat from the chaff. If you wish to have copies of any of those messages, I will gladly send them to you, suitable for framing. I didn't find any of them just now - but if you tell me where they are....I didn't know you were in the habit of posting to Martin Gibson and Spam threads.[sigh]"

2) "OK, Roger. I am so sorry for whatever you require me to be sorry for; and at the same time, I am especially sorry for whatever else I'm supposed to be sorry for. Does that make you happy? I DO want you to feel good about this.
....or was it Mmario or Big Mick or katlaughing or Catspaw that was supposed to be sorry? I'm so confused. What thing? What past?
Who cares?
-Joe Offer-"

3) "No, Roger. I see no need to apologize. I haven't found any of your words that were deleted, although I concede that one or two of your 8,362 posts may have been deleted, if they were in a thread that was deleted. I did a quick check, and found none. It's not an all-encompassing check, but a quick check shows nothing. You're back to quoting out-of-context remarks from 2003 - comments that make very good sense when read in context. You've gone looney again. It's time to go back into your hole. Goodbye, Roger.
Maybe you just don't get it. It's worthwhile to respond to you when you're reasonably rational, when you address an actual issue. When you resort to two-year-old, out-of-context quotations and ad hominem attacks and one-in-a-million situations, you've gone too far, and there's no reasoning with you. Then it's not fun any more. Go hibernate, and come back when you're ready to be rational.
-Joe Offer-"

1) Joe is saying that if you posted to an MG or spam thread the message is gone. So if you remember how many times you posted to whatever many of those threads, you've got the number right there.

2) Is irrelevant.

3) No WORDS in your posts were deleted, but some posts have gone along with entire threads. See #1.
The advice is still good.