“It’s important to understand how we got where we are today. In 1966, the unthinkable happened: a madman climbed the University of Texas clock tower and opened fire, killing more than a dozen people. It was the first mass shooting in the age of television, and it left a real impression on the country. It was the kind of terror we didn’t expect to ever see again. But around 30 years ago, we started to see an uptick in these types of shootings, and over the last decade they’ve become the new norm.
In July 2012, a gunman walked into a darkened theater in Aurora and shot 12 people to death, injuring 70 more. One of his weapons was an assault rifle. The sudden and utterly random violence was a terrifying sign of what was to come.
In December 2012, a young man entered an elementary school in Newtown and murdered six educators and 20 young children. One of his weapons was an assault rifle. Watching the aftermath of these young babies being gunned down was heartrending.
In June 2016, a gunman entered a nightclub in Orlando and sprayed revelers with gunfire. The shooter fired hundreds of rounds, many in close proximity, and killed 49. Many of the victims were shot in the head at close range. One of his weapons was an assault rifle.
Last month, a gunman opened fire on concertgoers in Las Vegas, turning an evening of music into a killing field. All told, the shooter used multiple assault rifles fitted with bump-fire stocks to kill 58 people. The concert venue looked like a warzone.
Over the weekend in Sutherland Springs, 26 were killed by a gunman with an assault rifle. The dead ranged from 17 months old to 77 years. No one is spared with these weapons of war. When so many rounds are fired so quickly, no one is spared. Another community devastated and dozens of families left to pick up the pieces.
These are just a few of the many communities we talk about in hushed tones—San Bernardino, Littleton, Aurora, towns and cities across the country that have been permanently scarred.”

Taken out of context in an Internet meme http://buzzpo.com/hours-after-paris-terror-attacks-meme-surfaces-that-calls-obama-out/. Two sources for the original quote are:
"At some point, we as a country will have to reckon with the fact that this type of mass violence does not happen in other advanced countries. It doesn’t happen in other places with this kind of frequency." * 2015-06-18
Statement by the President on the Shooting in Charleston, South Carolina
https://www.whitehouse.gov/the-press-office/2015/06/18/statement-president-shooting-charleston-south-carolina
"We are the only advanced country on Earth that sees these kinds of mass shootings every few months." * 2015-10-01
Statement by the President on the Shootings at Umpqua Community College, Roseburg, Oregon
https://www.whitehouse.gov/the-press-office/2015/10/01/statement-president-shootings-umpqua-community-college-roseburg-oregon
Cf. Obama in Paris on December 1st, 2015: "I say this every time we've got one of these mass shootings; this just doesn't happen in other countries." (Paris itself had just been "hit with a series of simultaneous terrorist attacks. The majority of 130 deaths were in mass shooting attacks, where the ISIS-affiliated terrorists attacked public places with automatic rifles." — as reported in * 2015-12-01
Obama Speaking in Paris: Mass Shootings ‘Don’t Happen in Other Countries’
Alex Griswold
mediaite.com
http://www.mediaite.com/tv/obama-speaking-in-paris-mass-shootings-dont-happen-in-other-countries/).
Misattributed
Variant: This [mass shootings] just doesn't happen in other countries.

Quoted by CNN, regarding the My Lai massacre. http://www.nytimes.com/2006/01/07/national/07thompson.html
Attributed

ACM Queue A Conversation with Alan Kay Vol. 2, No. 9 - Dec/Jan 2004-2005 http://queue.acm.org/detail.cfm?id=1039523
2000s, A Conversation with Alan Kay, 2004–05

Speech to the Aspen Institute ("Shaping a New Global Community") (5 August 1990) http://www.margaretthatcher.org/document/108174
Third term as Prime Minister

Page 256
The Conscience of a Liberal, 1962

Ours didn’t run to bloody horror. Ours ran to weirdness. We began to interpret dreams. Remember, Joe and I were wholesome characters. We weren’t guys that were bent on the weird and the bizarre. We were the kind of guys who wouldn’t offend our mother, who wouldn’t offend anyone in your family, and certainly not the reader. So we knew that we had to depart from adventure and that there were other ways to go and we came up with the “Strange World of Your Dreams”.
Context: page 4 http://www.tcj.com/jack-kirby-interview/4/ 1990, Gary Groth interview

Source: 1930s- 1950s, Landmarks of Tomorrow: A Report on the New 'Post-Modern' World (1959), p. 22