I really do own socks older then some of those that haunt these forums ...
Think the oldest socks I still use are in the range of just 10-12 or so years old.
Oldest clothing/fabric type of thing that I still own and use came from my time in the military though. They are my two pairs of black
"M90 Stridshanske" ("M90 Combatglove"... not sure if it's fake or real leather, they do feel "properly made" though, so probably good quality in general atleast... used for protection against wind, rain, snow, and some minor scrapes and bruises... not cold though, for that you had knitted gloves, which the M90 glove would fit over... dont think I have the knitted gloves we got in the military though)... and two long, but only about 8 or 10 inches wide, green towls that we used in the field (where only that wide for ease of packing). The second pair of gloves, and the two towls, where all
"borrowed on a permanent basis". XD
So agewise those things are 17-18 years old by now (depending on when I got them during my military training).