Hello newbie! I'm a grognard. But more of a 1st edition/2nd edition/Mentzer BECMI/Judge's Guild grognard who plays Pathfinder and 3.5 and owns Ptolus. There are other gornards here, but we don't have much in common. We have 3.5 grognards who likes Pathfinder. And we have other 3.5 grognards who prefers Pathfinder over 3.5 now, because they see it as 3.75. We have some 3.0 grognards who can't find anyone to play with, so they play 3.5. We also have other grognards who to me are too grognardy, and prefer older versions of original DnD like the Moltvay basic and expert sets. And don't forget our most grognard of grognards, diaglo, who believes that there is only one version of DnD (the 1974 original) and the rest are just pale comparisons. We also have a bunch of new grognards in development who like 4e but are about to get outdated and therefore grognarded by 5e. They are in denial, which may or may not also be a river in Egypt. We all like Dungeons and Dragons, however, except for the grognards that play Mutants and Masterminds and have a presence here and the grognards who like the original Traveller, because that would be weird, but cool.
Anyway, I'm glad I cleared this all up for you and welcome to ENWorld.