Revealing mistake: When David enters the food robot to escape, he makes a left at a cop car with the license plate 11385. A few moments later, he passes the same exact car going in the other direction. (00:41:40)
Revealing mistake: In the scene where Max challenges David to navigate the ship on his own, fingers are seen controlling the Puckmarin's movements at one point. (01:04:05)
Revealing mistake: Many times during the movie, when there is a close-up of the puckmarin, tiny wires can usually be seen attached to its arms.
Revealing mistake: When introduced to what David calls "Popcorn", the wires moving the puppet are visible.
Answer: I can't directly answer this, but I was watching this movie just now, and didn't take in the girl at the beginning's (Jennifer's) name, so when Sarah Jessica Parker, Carolyn, appeared I then spent the rest of the movie assuming that she was going to turn out to be the girl he was crushing on in 1978, especially when Carolyn even told him he was cute (which is kind of a weird thing for a 20-year old to say to a 12-year-old if there isn't a plot reason for it). I do wonder if that was in fact the originally intended idea that was changed for whatever reason before the movie was completed, and if perhaps he was meant to go back to 1978 with the knowledge that she found him cute and therefore a new-found confidence to ask 12 year-old her out.
MrDannyDetail