“Old fogey”is indeed pretty old. Nowadays, of course, it means somebody well up in years whose attitudes and opinions tend to be outdated — sometimes to the extent of being funny. If some old codger is heard complaining about “the kids today,” that’s a sure sign of an old fogey.
In the 1700s, a “fogey” was a soldier assigned to stay at the fort because of injury or illness. That meaning stuck for at least a century; a phrasebook from 1867 includes “Fogey, an invalid soldier or sailor.” “Fogies,” at least the kind who were soldiers, weren’t at first old. But by the late 1700s, “old fogies” had arrived: “Taylor, a pensioner belonging to the Royal Hospital, who proved that the traverser had made use of the imprecation and expressions charged in the indictment, and had abused him as an old fogy” (1793).
Once they arrived, the old fogies stuck around; “old fogey” has had the same meaning ever since. There are other varieties of fogies too — a plain “fogey” is somebody aged and dull, but perhaps not quite as crotchety as a classic “old” fogey: “I do hope they will have somebody interesting to dinner. Lady Sara looks to me as if all her friends would be fogies” (1908). And there are even young fogies, as pointed out by William James in 1899: “We call them old fogies; but there are young fogies, too. Old fogyism begins at a younger age than we think. I am almost afraid to say so, but I believe that in the majority of human beings it begins at about twenty-five.”
There’s one more kind of “fogey”, and it goes back to the association with soldiers — in the US Army, in this case. Here’s a good explanation from 1867: “…besides their regular pay, [soldiers] get an additional ration, or the value thereof in money, for every five years they serve. This is called the ‘service’ ration, or the ‘old fogy’ ration in the army.” The term seems to be still in use, or at least it was as recently as 1996: “Every two years, military members receive a year-of-service, or fogey, pay raise…”
Nobody knows where “fogey” came from. It might be from “fogram”, which is a pretty obscure word that means about the same thing. But this isn’t particularly helpful, since the origins of “fogram” are just as mysterious. There’s a theory that the US Army version of “fogey pay” is the origin of all versions of “fogey.” Since the word was in use before there was a US Army (or a US), this is not very likely. The word might have come from “foggy,” which in some Scottish dialects means decrepit. That’s essentially a guess as well, but it’s a better guess than the one suggesting the origin is the French word “fougueux.” “Fougueux” means fiery or fierce, which isn’t really a good description of any of the senses of “fogey.”
Whether or not we have any idea where “old fogey” came from, one thing is for sure. These darn kids today aren’t lifting a single lazy finger to figure it out!