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Remember the verb must be present tense so it would be : dragonslayer109 says, "You can learn a lot of cool stuff from me"

but that would mean you say it now, not that you said it a few hours back.

It is because you are quoting it from text so if that person had to read the quote for the first time it is as if I had said it again right now. Try not confuse it with direct and indirect speech as that is a different concept to quoting.