- Author Existence Failure: Ken Grimwood was writing a sequel when he died in 2003.
- Development Hell: Ben Affleck and Robert Zemeckis have been attached to direct a film version at Warner Bros., which seems to have been put on hold due to Affleck directing Argo and Zemeckis directing Flight.
- Technology Marches On: With appearances of the Wang 1200 and Sony VTR. The following quote happens in 1974:
"Near the window was a large desk stacked with books and notebooks, and in the center of it sat a bulky, greenish-gray device that incorporated a video screen, a keyboard, and a printer. He frowned quizzically at it. What was she doing with a home computer so early? ... 'It's not a computer,' Pamela said. 'Wang 1200 word processor, one of the first. No disk drive, just cassettes, but still beats a typewriter. Want a beer?'"
- Unintentional Period Piece: Written in the 1980's, when people would find many of these events nostalgic. Now that it has been over 25 years since it came out, it's more of a time capsule of the 25 year period.
- What Could Have Been: Grimwood was working on a sequel when he died on June 6, 2003. He died of a heart attack, so one could hope he wrote it during his next replay...
- Only four known replayers are found during the 1963-1988 era. Jeff, Pam, Stuart and the one from Australia who sent the cryptic letter Pam and Jeff received.
- The Internet gives you to ability to watch the plot-important 1963 Kentucky derby - a luxury the author probably didn't have in the early 1980's. Seeing as many tropers these days weren't even born by 1988, the Internet gives you the ability to look up many of the events and technology covered in the book.
- Jeff is 43 in 1988, meaning he was born in 1945.
- All told, Jeff was 202 years old at the end of his replaying - that's the equivalent of living from his birth year of 1945 to 2147. He had ten replays totaling 159 years.
- The "skew" is small until his fifth replay, when he is a full year off (leaving 24 years). The next three replays are 4 years shorter (a 20-year replay), 8 years (a 12-year replay), and 9 years (a 3-year replay).
- If Jeff is still alive by the 2017 date in the epilogue, then he would be 72 (227, factoring in his replays).
- This page was created in December of 2011 - a mere six years short of the replay date of the man in the epilogue.