1. According to Danny Boyle, the link between all of the segments in the opening ceremony is "the idea that we can build Jerusalem. And that it will be for everyone."
2. The turf you see at the start was real – all 7,300 square metres of it.
3. All of it was removed by performers from the stadium floor in just 15 minutes.
4. Many of the 10,000 performers in the opening ceremony were volunteers who rehearsed in their spare time and had no previous dancing or acting experience.
5. Practice took place in the stadium, but also in a large car park in Dagenham, east London. Auditions and first rehearsals took place at 3 Mills Studios.
6. The bell you hear at the very start of the ceremony was made by the Whitechapel Bell Foundry, which is the oldest manufacturing company in Britain, dating back to 1570.
7. The bell is inscribed with the words "Be not afeard, the isle is full of noises", from Shakespeare's The Tempest. These words were read at the ceremony by Kenneth Branagh, who was playing Isambard Kingdom Brunel.
8. After the ceremony, it was put into storage for four years but has since been erected in the Olympic Park, not too far from the Olympic Stadium.
9. Brunel was originally supposed to be played by Mark Rylance, but he had to pull out several weeks before due to family reasons.
10. Many viewers, particularly in the US, thought that Brunel was Abraham Lincoln.
11. When the camera zooms into Kenneth Branagh's face [above] towards the end of the Industrial Revolution sequence Frank Cottrell-Boyce, the writer of the opening ceremony, believes his expression is an amazed reaction to what is happening rather than him acting.
12. Relatives of notable suffragettes were invited to be in the audience for the sequence.
13. The towers that came out of the ground were not from holes. They were inflatables that were pumped full of air with the height controlled by wires above.
14. The pause during the Industrial Revolution sequence is supposed to reflect all wars in all countries throughout the world, not just World Wars I and II.
15. What was not shown on camera was that during the memorial pause, everyone in the audience stood in silence.
16. The BBC and Danny Boyle met before the opening ceremony to discuss the commentary, over concerns that it would drown out the music.
17. A team of performers were underneath the rings when they collided, and there were concerns that they would be burnt. They were told to shake the embers off.
18. If it had rained, the flames falling from the Olympic rings would never have happened.
19. For the next sequence, "Happy and Glorious", in which the Queen met Daniel Craig, Danny Boyle and his team were planning to cast a double if the monarch said no.
20. The Queen agreed before Craig did, due to complications in his schedule.
21. Paul Whybrew, the guy who introduces the Queen to James Bond in “Happy and Glorious”, is her actual footman.
22. They managed to film the Queen sequence at Buckingham Palace in two takes, in the room where she normally meets prime ministers.
23. The Queen was not supposed to say anything in the film, but she asked if she could.
24. The Sun reported that Daniel Craig had been spotted walking into the palace earlier that year, but as the piece was published on 1 April a lot of readers thought it was an April Fool's joke, so it didn't become common knowledge.
25. According to The Times, two dresses were made for the Queen: one for the real monarch and one for the stunt double who jumped from the helicopter.
26. The Queen and Bond were originally supposed to land in the stadium itself, but due to concerns about the overhead wires, Boyle decided they should land outside.
27. A BBC documentary on the Olympics claims that health secretary Jeremy Hunt, who was then the culture secretary, wanted to reduce or cut the NHS sequence entirely. A spokesman for Hunt denies this and says that he was only concerned about the show's length so that people would get home safely.
28. Nearly all of the volunteers for the NHS sequence were doctors and nurses. Many had gone straight from night shifts to rehearsals.
29. During the ceremony itself, nine patients from Great Ormond Street children's hospital were invited to appear on the hill in the stadium and watch the sequence.
30. JK Rowling was terrified to speak when the children went to bed in the NHS sequence, but agreed to do so because she values the importance of children's literature.
31. The "Memorial Wall" sequence, where pictures of people who had died came up on a screen, was thought up by Danny Boyle. His late father's birthday would have been on the same day as the opening ceremony.
32. Volunteers, members of the production team, and the audience were encouraged to commemorate a friend or family member who they wished could have been there.
33. Boyle wanted to include a tribute to the BBC in the ceremony, but felt it might have been a "conflict of interest" as the ceremony was broadcast by the corporation.
34. The family in the middle of the "Thanks Tim" sequence, which celebrated British music and the inventor of the World Wide Web, Tim Berners-Lee, were all volunteers.
35. The giant house in the middle of the stadium [above], was also inflated seconds before the sequence took place. A second house was made of foam.
36. When Tim Berners-Lee was unveiled under the house typing on a computer, words saying "This Is For Everyone" were published on his Twitter account.
37. The US broadcaster NBC had no idea who Tim Berners-Lee was. Ironically, presenter Matt Lauer told audiences watching in the States to "google him."
38. There were great concerns that the Athlete's Parade was going to be too long because it cannot be rehearsed.
39. The drummers from the Industrial Revolution sequence became marshals and were asked to bang to the drums to keep everyone moving.
40. Unfortunately, one cast member got too excited and walked out in front of the Indian athletes when they marched out, and then had to apologise.
41. The tote bag the mother carried when she opened the door in the “Thanks Tim” sequence was the same pattern as the outfits the marshals wore during the Athlete’s Parade.
42. The confetti that fell when Great Britain marched out was in 7 billion pieces, supposed to represent every single person on Earth.
43. There were nearly 1000 cannons firing out confetti, in total 300kg of the stuff.
44. Each of the 204 countries that participated walked out during the Athlete's Parade with a copper petal. The petals were then secretly taken underneath the middle of the stadium to be attached to the Thomas Heatherwick-designed cauldron afterwards.
45. Each petal was inscribed with the name of a country participating in the Olympics.
46. The cauldron had to be extinguished not long after the ceremony so it could be moved to the edge of the stadium for the athletics, but a flame was kept in a miner's lantern and the cauldron was then relit by a torchbearer from the 1948 games.
47. The cauldron sequence was rehearsed many times in middle of the night so it wouldn’t be spotted by volunteers and newspaper photographers. There was a no-fly zone imposed above the stadium during testing.
48. Paul McCartney did his soundcheck the night before the Opening Ceremony and played "Let It Be" for the 50 or so people who were working on the stadium floor that night.
49. The emergency backing track was out of sync for Paul McCartney's performance at the end of the ceremony, hence why it sounded a bit crap for 10 seconds.
50. Overall 27 million people watched the opening ceremony in Britain. More than 19 million people were still watching the ceremony passed midnight.
Watch One Night In 2012: An Imagine Special on BBC iPlayer and on BBC Four this Thursday at 10pm.
The Rio 2016 Opening Ceremony will be on BBC One, Friday 5th August, starting at 11.35pm.
You can buy the BBC DVD for the London Olympics here – make sure you listen to the Danny Boyle commentary option for extra facts.