Doc Brown: Here's a red-letter date in the history of science, November 5th, 1955. Yes of course, November 5th, 1955!
Marty McFly: What, I don't get what happened
Doc: That was the day I invented time travel. I remember it vividly. I was standing on the edge of my toilet hanging a clock, the porcelein was wet, I slipped, hit my head on the edge of the sink. Ad when I came to I had a revelation, a picture, a picture in my head of this. This is what makes time travel possible. The flux capacitor.
Doc: It’s taken me almost thirty years and my entire family fortune to realize the vision of that day, my god has it been that long?