For those who haven't had "Home Alone" on repeat every holiday season since its 1990 release, the scene in question essentially opens the film and sees the McCallister crew gathering around a grande pizza feast. It also finds them prepping to catch their early international flight the very next morning. The scene is chaotic enough, but things go majorly sideways when 8-year-old Kevin gets into a tussle with his big brother Buzz (Devin Ratray), the result of which spills a river of milk all over the kitchen counter.
The aftermath of that event finds Kevin banished to the attic as punishment, and that's exactly where he is when the rest of the family dashes off to the airport without him. They actually don't realize he isn't on the plane until mid-flight, a fact that no doubt left some viewers wondering how the family didn't notice they had an extra ticket when they were checking in at the airport. If you're among them, you'll want to pay closer attention to that pizza disaster scene the next time you watch the movie. There is actually a brief shot of Kevin's milk-soaked ticket being accidentally tossed in the garbage amid the clean-up.
That cutaway is easy to miss in all the chaos, but it could not be more important to legitimizing how Kevin got lost in the shuffle. As for everything that follows, willful suspension of disbelief is still the order of the day for most of those shenanigans, and that's okay by us.