As a member of the Sydney Cricket Ground, I now have to wear more formal clothes (a collar and non-sneakers) to the cricket or football there, than I do to a play or opera at the Sydney Opera House.
The first wedding I performed was on a Halloween in a cemetery. I rented a tuxedo and went all out with the vampire look. Black nail polish, the works, with the help of a cosmetologist friend. I kept things understated.
After solemnizing vows and a punk reception I realized I needed gas. I had to pay before I pumped and that was awkward.
In 1967 I was in San Francisco on IBM business and took time to hit the Haight Ashbury and see the summer of love. I wore the IBM uniform - 3 piece suit with white shirt and tie. The hippies called us out as members of a dying culture with phallic symbols around our necks.
Hospital Intensive care unit.
My wife’s grandfather had a heart attack a few days before our wedding (he had delayed going in, hoping to see it, but it was too bad to ignore).
After the ceremony we went in our wedding clothes – my wife in her wedding dress and me in my suit – to visit him so he could at least see that.
In '92 (I was 48) I discovered swing dancing, and eventually took lessons and danced my ass off for the next fifteen years. When I started the venue was 100-150 dancers every Friday night, and most of the men showed up in outfits like shorts and sandals (with socks!) or with jeans and tees if they were feeling dressy. I finally showed up in a jacket and tie, and in a month, half the guys had switched. Dressing up was never a problem for the women - none of them ever came looking like they dressed from a ragbag.
Dan
I had the same experience with my extended family.
Back in the eighties, my prom date and I both worked at the same McDonalds, so of course we stopped by there in our glad rags to show all our buddies. Some of the customers looked scandalized, like, “Girrrrl, you worth more than a Big Mac!” 
I took a public speaking class in college and anytime I had to give a speech I would wear a suit as I had been taught in my high-school public speaking classes. I was only mildly out of place in that class, but it definitely made me stand out in my other classes those days.
Dick Nixon had beach attire nailed.
Baah, that’s completely informal. Might as well be in shirtsleeves.
Not me, but I’ve seen people go to a Gwar show wearing white tuxedos.
Richard probably used these as pajamas.
I was offered free tickets to Stevie Nicks, so I went with a group of friends. There were a few women there wearing wedding dresses. (and what a horrible show. She had throat issues and apologized. She’d sing the first line or two of a song, then ask the audience to help her out and they did. )
Dentist and Visionworks. Prior to COVID, I regularly scheduled my annual optical exam and a quarterly dental exam on the same day as a lunchtime holiday party; dental before the party and optical after.
A story I heard. I started out as a draftsman. Ink on mylar, sometimes just pencil. At one company (never worked there) the draftsmen, all came into work wearing ties as a joke. The big boss said “Fine, you will wear ties every day”
This was a mapping company where you have huge maps and drafting tables that you have to constantly lean over.
Drafting, with a tie on? No just no.
A county fair.
I was about 17 and I asked this girl that went to our weird church for a date. I was going to take her to a decent restaurant so I wore dress pants and a jacket & tie. When I picked her up she said she would rather we go to the fair and eat corn dogs and cream puffs.
I ditched the jacket and tie but was still wearing a long sleeve shirt and dress pants/dress shoes while walking through barns. And it was July.
ETA: I dated her one more time, taking her to a dance, before I determined she was a total bitch. Just rude and unkind to everyone.
Hah! In the 90s I worked for a guy who was a bit weird. I decided to wear a tie every day because I had a fairly big collection and I was a bit weird. Well, the boss man copied me and began wearing a tie every day. My coworkers found the situation hilarious. Other people noticed as well.
Should have started to have Tux Tuesday, and see what the boss would do.
My bathroom at home.
I am really surprised nobody else has done this. Am I weird?
Wife and I got married at a Las Vegas casino - just us, no guests. Immediately after the ceremony, we drove to a bakery across town to pick up our cake. I don’t recall whether there were any other customers there, but if there were, they certainly weren’t wearing a tux and gown like we were, and neither were the staff.