The first concert I went to was also the Who – 1970, the Who’s Next tour. 
I also have a school tie, which I bought as a freshman in 1981, and a pair of gabardine suit pants I got new in 1992 (let out repeatedly since).
My mom still has my baby clothes from 1966, if that counts.
Mine? A knit striped double v-necked shirt I made when I was in - er - 7th? grade. That’d be 1978 or so.
From someone? A mink stole (which I wear when I get gussied up) that was my grandmother’s - 1930’s maybe?
a stone marten neckpiece that was my mother’s - circa 1948.
VCNJ~
My great-grandfather’s Chicago overcoat. Wonderful grey coat, wool, very classy (would like fine in a gangster pic!). It fits me and shows minimal wear (couple of loose threads and I had to sew two buttons back on). Still has the tailor’s label inside, when I went to school in Urbana IL I tried looking them up but I guess they are out of business.
Wore it in the winter sometimes and it was really nice. I don’t know exact age but I’m betting it’s more than 60 years old (I’m 36).
The oldest thing I own would probably be a Members Only jacket I have hanging in the back of the closet that dates back to the mid-80’s, but it’s never worn. Of the things I still wear, I’ve got a T-shirt from Daytona Beach Bike Week, March 1992. A close second would be my 80th Grey Cup shirt (also 1992, but from November). Neither is in my regular rotation, but they’re both in good shape and I still put them on from time to time.
Bottom half of US Navy issued thermal underwear I got at Great Lakes, Ill. in 1967.
Haven’t been worn in many years, but remain on my closet shelf.
I still wear my father’s Navy peacoat that was issued to him in 1945. His father wore it from 1946 until the early 60s, so 3 generations have beat this thing up. I think it can withstand bullets.
The oldest thing I got on my own are several t-shirts from musical events circa 1982.
As an aside, I clearly remember trying on that peacoat every fall starting at age 10 or so, until I finally fit into it at 16.
My daughter has adopted my sister’s wool coat (with the wooden barrel buttons) from circa 1972, it’s almost five times as old as she is.
I have a shirt from the first unit I was with in the Marines, from January 1995. I still wear it, actually in pretty good condition.
My sister gave me a Levi’s denim jacket in 1975.
While it hasn’t always fit, it fits now.
Still in general rotation (in fact, I’m wearing it right now): A t-shirt from Kix’s 1991 Hot Wire tour.
Still own, but just for nostalgia purposes: A zebra print jacket from when I was a long-haired rock star wannabe, purchased in 1986.
Still own, and put on every now and then just to see if it still fits: A gym shirt from sixth grade. It’s a little snug, but yeah, it still fits.
I’ve still got the suit I got married in, from 1978. I more or less can still fit in it, but don’t wear it. I also still have the tie, which I do wear about half the time I wear ties (once a year.)
I’m not sure this counts, but I have a tie tack I got at my bar mitzvah, which I still use. That’s 1964. I have some boots that might be from college, but I’m not sure, and I still use the ice skates I got in college.
i have a suede sport jacket, circa 1970, that belonged to my father… i don’t remember him wearing it in my lifetime, but after he passed away, my mom dug it out of the closet, and hey, it fit me! i have given it regular use in the past almost two years since i recieved it.
While rooting around in the basement for old clothes that might fit me again, I found-
A t-shirt from a play I was in when I was four years old. There’s no way it fit me properly back then- it must have been pretty huge on me. Right now, though? perfect.
And a little sundress that must have been from when I was around two. It also must have been sort of baggy back then… it’s one of those garments that’s wider than it seems like it should be. Anyway… on a whim, I pulled it over my jeans and it fits around my waist. It’s long enough that I COULD wear it alone, but short enough that I never would. I cut the straps off, so now it’s more like a proper skirt. I’ve worn it over my jeans a couple times.
So the shirt would be eleven years old and the dress/skirt would be around thirteen. Which isn’t all that impressive on its own, but that’s 73% and 87% of my life, respectively.
I have a shirt that I bought 14 years ago, when I was 16. It’s out of fashion, ugly, too small and I’ll never wear it again but I’ve had it too long to throw it away! Still, it’s just one small garment, I don’t see the harm in keeping it as long as I don’t make a habit of it.
I am right now wearing a navy and green jacket that originally belonged to my first husband.
It’s been 30 years since we split up.