You know what frustrates me the most when reading RPG forums? Seeing a post about something cool and, to me, new and useful, and then seeing a bunch of people dogpile it with “but that’s so obvious, I’ve been doing that for years and I don’t need anyone (or a set of rules) to tell me to do that.”
You know what? Bully for you. That doesn’t mean that the forum post, theory idea, or ruleset wasn’t useful to as many or more people, including me. Just because you already know something is no reason to pooh-pooh it when someone else points it out.
This tactic is used a lot in the internicine flamewars between “Forge” people and “traditional” gamers. Mostly it gets aimed at the Forge side as a way of “deflating their egos” or pointing out that their not as hot as they think they are, but it goes the other way too (and Forge supporters have their own favoured rhetorical tactics that are just as annoying, like [sweeping generalization alert] asking for definitions until the other party gets sick of it).
Shut up. If you’ve known it for twenty years, why didn’t you post about it first? It’s not that obvious, if only because there are newcomers to the hobby all the time, and they could stand to see these sort of remedial tips that they don’t even know enough to ask for.
Get over yourself, like yesterday.