Why did Zed tell Jay that the black MiB suit is the "last suit" he'll ever wear?
Zed: Edwards! Let's put it on.
Jay: Put what on?
Zed: The last suit you'll ever wear.
Why did Zed tell Jay that the black MiB suit is the "last suit" he'll ever wear?
Zed: Edwards! Let's put it on.
Jay: Put what on?
Zed: The last suit you'll ever wear.
I think Zed is alluding to two aspects of life as a Man In Black:
On both counts Zed may not be entirely serious. Kay certainly enjoys some deadpan mockery of their new recruit, and Zed could be doing so as well.
Aside from the fact that it is core to the Men In Black mythology in general - they're omnipresent, even if not noticed, but you can always identify them from their identical suits ... I've actually always taken Zed's line to be a bit morbid:
Because that's the suit you wear on the job, and you're probably going to die on this job, and then we bury you. In that suit.
Making it literally the last suit Jay will ever wear.
It's largely a hyperbolic statement.
We know that MiB's are allowed to retire. Just within (and between) the movies, K's previous partner does. K does. L does. T does.
We know that they're not referring to that specific suit because they have extras in their lockers
Let's look at what exactly Zed says. From the script (note that the final theatrical version was slightly different, omitting the part about expenditures):
ZED Then let's put it on.
EDWARDS Put what on?
ZED The last suit you'll ever wear.
CUT TO:
INT. MIB BUILDING - LOCKER ROOM - DAY
Like the rest of the place, the MIB locker room is all white. White walls, white floor, white ceiling, white lockers. ZED'S VOICE comes over:
ZED (O.S.) From now on, you'll dress only in attire specially sanctioned by MIB Special Services.
EDWARDS reaches out and opens a white locker, revealing a BLACK SUIT hung from a hanger in the middle. Above it, on the shelf, a BLACK HAT and a pair of BLACK SUNGLASSES. On the bottom, a pair of SHINY BLACK SHOES.
INT. MIB BUILDING - HEADQUARTERS - DAY
KAY is at a computer terminal. On screen are EDWARDS's birth certificate, driver's license, social security card, library card, everything. ZED'S VOICE continues:
ZED (O.S.) You'll conform to the identity we give you, eat where we tell you, live where we tell you, get approval for any expenditure over a hundred dollars.
INT. MIB BUILDING LASER BOOTH - DAY
EDWARDS stands in a cramped white booth.
He holds both his hands on a TEN-FINGERED KEYPAD, pressing down hard. The pad glows red, a SEARING sound comes from his hands, and he grimaces as more lasers instantly and (not at all) painlessly change his fingerprints.
ZED (O.S.) You will have no identifying marks of any kind. You will not stand out in any way.
INT. MIB BUILDING - HEADQUARTERS - DAY
One by one, KAY deletes EDWARDS's identity cards.
On the computer screen is EDWARDS' full name -- JAMES DARREL EDWARDS III. Kay punches a couple keys, and the cursor begins to sweep from right to left, starting to eliminate the rightmost letters of EDWARDS's name.
ZED (O.S.) Your entire image is carefully crafted to leave no lasting memory whatsoever with anyone you encounter.
INT. MIB BUILDING - LOCKER ROOM - DAY
Pants come off the hanger. The white shirt is removed.
More letters are eliminated from his name. It reads "JAMES DARREL ED..." then "JAMES DARR..."
ZED (O.S.) You're a rumor, recognizable only as deja vu and dismissed just as quickly. You don't exist; you were never even born.
The coat is removed. The hat comes off the shelf.
ZED (O.S.) Anonymity is your name. Silence your native tongue.
"JAMES..." "JAM..."
ZED (O.S.) You are no longer part of "the system." We're above the system. Over it. Beyond it.
Feet slip into black shoes. A belt is buckled. A tie pushed up.
ZED (O.S.) We're "them." We're "they."
On screen, all that's left is the letter "J."
As the coat is buttoned, we notice the sleeve. Monogrammed on the cuff is, simply, the letter "J."
MiB agents do not officially exist. To maintain that secrecy, they are only allowed to live in certain places, only allowed to eat in certain places, and are only allowed to wear a specific uniform. They're not allowed to wear any other suits.
The key phrase here is:
ZED (O.S.) From now on, you'll dress only in attire specially sanctioned by MIB Special Services.
The suit he has just been given is the last one he will ever wear because it is the last one he will be approved to wear (probably barring replacements or updated uniforms).
Well seeing as this is a secret government agency, and when he's getting his fingers burned off erasing him from the "system". you can kind of put together that he no longer exists, and that this will be his last job, because if you notice in the beginning once you get too old, or no longer suitable for the job anymore your mind gets wiped and your no longer in the system, just retired. (hence, last job, besides close watched retirement)
To counter some of the more morbid answers here, we could also dive in to what "you" means. Post retirement neutralization Jay is certainly a different person than the Jay standing there, stepped in the secrets of the MIB. It's a Jay who took another path and never wore that suit to begin with. In that sense, knowing that Jay could never leave the agency without losing the part of his memory that ever knew about it, this suit is truly the last one he will ever wear—regardless of how his life ends.
K's parnter retired at a very old age. While most MiB agents might die in the line of duty, as several answers suggested, it's unlikely that he'll ever have to put a suit on for another job again after he retires.
Same with K. Although he wound up working at the post office because he apparently couldn't give up working, it's likely that both J and everyone else thought that he'd give up working forever after he returned to the life he lost.
But then they wouldn't have had MiBII.
Strange. Somehow I always assumed that MiB's access to extraterrestrial tech meant that these were indestructible suits - self-cleaning, self-repairing, etc. - so they were the last suit you would ever wear because they would never need to be replaced. The other answers are just as plausible, though [and they are not mutually-exclusive answers, either...].
I thought that 'The Last Suit You'll Ever Wear' was the advertising line of some clothing company... meaning that the suit is of such good quality that the purchaser will wear out before it will, and it is of such a classic design that one will never want to buy another suit since that one looks so good. This would probably be also quite depressing since it will remind the buyer of their impending mortality.. I believe there was a joke in the USA that FBI agents always wore dark or black suits. These were a byword for conformity and dullness, especially in the swinging 60s when the cool people were wearing jeans and bright colours.. - hence the proverbial people in the film title. FBI agents would then use the slogan as a joke about how dangerous their job was - ie. They were likely to be killed in the line of duty before the suit wore out.... The Men in Black idea is a myth based on the half truth that if you do anything that the government don't like , you will be visited by two G Men, FBI agents, or similar, wearing the proverbial suits, so that they can persuade you of the error of your ways. This might not be true but all the above seemed obvious to me when i heard the line in the film.. maybe i've just got a wierd imagination..
NB 'Wesley Swearingen, a special agent from the earliest days of the (F) Bureau (I), described of the day he was handed his credentials and gold badge: “I glanced around the room at the men. We were all white Anglo-Saxons. Except for the difference in ages and body sizes we all looked as if we had come from one mold.” They were considered “Mr. Hoover’s personal representatives,” and were given a strict dress code and set of grooming standards that, at least in the collective imagination of popular culture, continue to this day. Wrote Swearingen, “Mr. Hoover expects each of his Special Agents to wear a dark business suit, a white shirt, a dark conservative tie, dark socks, and black shoes. ....…. We were to hear about Hoover’s dress code hundreds of times over the years.” From https://news.clearancejobs.com/2014/09/07/how-j-edgar-hoover-built-an-fbi-to-last-part-1