Marty's parents are supposed to meet when his father is struck by a car. By preventing the accident, Marty inadvertently stops his parents from meeting and falling in love.

After her father hits Marty with the family car, she sees "Calvin Klein" on his purple underwear and assumes it's his name.

When he meets 11-month-old Joey in 1955, staring through the bars of his playpen, Marty says, "So, you're my Uncle Joey. Better get used to these bars, kid."

Marty identifies himself as an extra-terrestrial named Darth Vader from the planet Vulcan.

Marty's iconic performance of "Johnny B. Goode" calls on some classic moves from rock & roll history. In a few short seconds, he hits all the legends: Chuck Berry's one-legged hop, the windmill made famous by The Who's Pete Townshend, playing behind his head like Stevie Ray Vaughan and bringing the show to a literal standstill with a Jimi Hendrix/Van Halen-inspired solo. Go Johnny, go.

The clock tower is struck by lightning during an electrical storm on November 12, 1955, which fuses the clock's internal mechanism and stops it permanently at 10:04 pm.

When Marty returns to the future, he watches in horror as Doc gets mowed down again. But Doc is unharmed, having listened to Marty's warnings in the past and worn a bulletproof vest.

The vanity license plate used in the film reads "OUTATIME". When Doc returns from 2015, however, it has been replaced with a barcode license plate, implying that the DMV has updated its registration-tracking technology.

The script was rejected over 40 times by every major studio and by some more than once. "We'd go back when they changed management," screenwriter Bob Gale would later reveal in an interview. "It was always one of two things. It was 'Well, this is time travel, and those movies don't make any money.' We got that a lot. We also got, 'There's a lot of sweetness to this. It's too nice. We want something raunchier like Porky's. Why don't you take it to Disney?'"

Principal photography began in November 1984, but a few weeks into filming, Zemeckis realized Stoltz had been miscast. Although he and producer Steven Spielberg realized that re-shooting the film would add $3 million to the $14 million budget, they decided to recast.