I don’t remember most dates of world or national events, but I remember things like the day I met someone special. Probably because I didn’t want to be the kind of guy who forgets anniversaries.
4/12/08
8/19/99
6/4/95
4/22/93
April 5, 1994, the day Kurt Cobain died. It was weird because it was the first time I’d experienced the loss of one of “my musicians.” First time I had to realize one of my favorite bands was over. And the way in which he did it was pretty crazy for a 15-year-old.
May 23, 2009 I got finally got that incredibly expensive piece of paper that I’d been wanting for four years, and got to wear a silly hat all morning.
December 11, 2007, my childhood dog was put to sleep. 
June 28, 2006 was the day I arrived in London, and marked the beginning of the best six months of my life.
August 24th, 2004 was the day I left for college, and also marked a new record in “furthest from home I’ve ever been on my own”.
February 1, 2003 - both my parents were out somewhere that morning, and for some reason I wasn’t at my typical martial arts class, so I turned on the TV over breakfast just in time to hear that Columbia was gone.
And September 11, 2003 was probably one of the strangest days of my life, for reasons tangentially related to what happened on that date two years prior, but also involving horrible, horrible similes (“This school is like a racehorse”, said by our school principal), a bomb threat at school, getting the day off school, getting free water ice “for freedom”, getting questioned by the cops, and eventually I got punched in the face by a 200-pound man. Some of the above were directly related, others were not.
JFK assassination. My second grade teacher was called into the hallway. I sat next to a girl named Kim (quite the cutie, by the way) who had ears like an eagle and whispered “President Kennedy” to me. Moments later the stunned teacher told the class of the news.
RFK assassination. By now in 6th grade, I was awoke by my mother a bit early for a school day. She told me the news and watched some of the TV coverage until I had to go.
Man on the Moon. Having to go to my aunt Cora’s house and practically begging to be allowed to watch the coverage.
Challenger. A coworker told me the shuttle crashed. I didn’t see any video until I got home. That was before the internet, of course.
Columbia. My son was wrestling in a tournament. I came home between matches and my mother told me to turn on the news.
Wedding day. Of course
Birth of my son. One of the most beautiful things I ever saw.
Birth of my daughter. Ditto.
Death of my dog. He was old and could barely move. We arranged for a vet to put him down in our house.
All presidential elections since 1964. Relief…Disgust…Utter disgust…Wild Optimism…Shock and outrage…Resigned Disgust…Contempt…Wild Optimism…Joy…Shock and disgust…Outrage and Utter Disgust…Unbridled Joy.
The day my mother died. The day my son died. The day my son was born. The day I got married. The day my wife left. The day she came back. The day I was in a bad car wreck and, through a series of misunderstandings, spent the weekend locked up for “psychiatric evaluation.”
The day that “Tank Man” stopped the tanks in Tiananmen Square in Beijing (I had to look up the actual date - June 5, 1989)
One a bit wider scale, the whole Tiananmen Square Massacre. I was just becoming aware of global politics, and this shocked me. I remember being in a pet store, looking at fish tanks, when the news came out.
Challenger explosion - Looking back now, the feelings I had watching the explosion on TV remind me of what you hear on the tapes of the Hindenburg explosion.
I-35W bridge collapse in Minneapolis (August 1, 2007). The whole evening was spent calling people and being called, as everyone checked up on everyone else.
December 6, 1989: the École Polytechnique massacre.
June 27-28, 1969: the Stonewall Riots.
October 14, 1966: inauguration of the Montreal metro.
January 8, 2000: the date I moved out of my parents’ place.
I watched Challenger explode in the sky, not on TV, and I still don’t remember the date. I’d say that affected me pretty tremendously, though. I remember it very vividly and had bad dreams for years (still have one from time to time).
That ranks up there memorable-days wise with my weddings, the day my son was born, etc.
23 March 1994 was the date of the Green Ramp Disaster at Pope AFB / Ft. Bragg, NC.
Although I was pretty badly injured, I got very, very lucky. It was the closest I’ve ever come to being killed, and that’s saying something.
Can I just say how really f&cking creepy it is to see my birthday on a list like this?
The first space shuttle launch, April 12, 1981. Being tech-minded, launches nowadays still are newsworthy to me, but back then, this was the first of its kind. I was 11 at the time, and so it was the first manned US spaceflight where I was old enough to have some real appreciation for what was happening.
The loss of the Challenger in 1986 was odd to me at the time. Our school treated it incredibly seriously, with official announcements by the teachers to their classes, the wheeling in of TV’s so we could watch live coverage of the aftermath, and so on.
Of course I remember many of the fateful days already listed…but I also remember a day of happiness, and have kept the specific date in my memory all these years.
On June 6, 1959, my dad took me to a Cleveland Indians baseball game. The Indians lost – I’m afraid I haven’t retained the memory of the score, but I know that The Yankees beat them, and that Bob Turley was on the mound for the Yanks.
I’m not sure if this was my first baseball game, but it was surely one of the first. I’ve had a lifelong love of the game from that moment forward, and today my own son and I love nothing more than going to games together.
The funny thing (because I generally don’t attend more than four or five games a year) is that, by sheer chance, I also went to Indians games on June 6, 1999 and June 6, 2009 – the 40th and 50th anniversaries of the original game.
My first thought on reading the thread title: November 22, 1963, when JFK was assassinated.
I was in 4th grade and it was the first “big” thing to happen in my life. It was a bit overwhelming for my little brain and very emotional and I will never forget it.
There have been many dates/days that I remember well, but that one is the biggest.
May 10, 1976, my grandmother passed away, now her 3 day Irish wake is a slight, blur but still memorable.
The weekend of July 23, 1976, spent with my father and my younger sisters on a trip to Washington, DC, saw the sites, went to a concert at the Jefferson Memorial, was told to stand at attention while they played the “National Anthem”, twas the Marine Corps Hymn, 
but my dad is ex-marine so we let it slide:D, May 18, 1980 Mount St Helen, July 11,1987 married, Jan. 24, 1989, birth of son, July 2, 1993, my father passed away the 2 weeks following were also memorable, impromptu family reunion- if anything could go wrong fest, my dad didn’t want any sadness with his passing, well he got his wish:D.
Like many here I remember many of the space milestones, most of all 7/21/1969. I was eleven, and painted a picture of it since I had recently been given an oil paint set.
I was only three when the first American astronaut flew in space, but I’m pretty sure I remember my mother telling me, “There’s a man in this one.”
The first Columbia launch was another big one. I had just graduated, but was back on a visit to my old college, which was known as a “nerd” school. Sure enough, in the room I used to live in they had three TVs showing the coverage on different networks, while working out the trajectories on their TI calculators. Good times, indeed!
I remember this, too, but only because I was out of town at the time. While on a visit to greater Chicago, my cousin and I were on a mini-road trip up the lakeshore, as far as Manetewoc, WI. (You have to see this part of the country to know that “brat frys” are not an extreme form of tough-love.) We stopped for beers and there it was on the bar TV; it seemed odd that it was still daylight on the tube though it was dark where I was, with sunlight on the palm trees and this bizarre slow chase going on.
10/17/89, 5:04 p.m. Loma Prieta earthquake. To this day, when I glance at the clock and see that it’s 5:04 p.m., I notice it.
The Challenger explosion (though like others I can’t remember the exact date).
The day John Lennon was shot (I’m not a big Beatles fan, but I remember what a big deal it was).
The day Princess Diana died. We were preparing to take our first-ever trip to England only a couple of days after that–we were in London the day of the funeral, and saw the procession go by.
The day Reagan was shot. Again, I don’t remember the exact date (though I do remember it was in 1981)–I was in French class in high school when I heard.
The day Nixon resigned (August 9, 1974.)
Columbine.