Title text: I'm teaching every 8-year-old relative to say this, and every 14-year-old to do the same thing with Toy Story. Also, Pokemon hit the US over a decade ago and kids born after Aladdin came out will turn 18 next year.
Uncle Rob is telling his eight-year-old nephew a ghost story, employing such stereotyped devices as a flash light-lit face and stock ghost story endings. Normally you do not look for the head of a ghost, but of a body - then the ghost may be a headless one.
Rob's precocious nephew thus characterizes the ghost story as "lame," meaning that it was unimpressive or unconvincingly feeble. His uncle Rob ask him if he can come up with something scarier. Sure he says and offers the much scarier notion that even though he has been born after 9/11 he is already old enough to be able to have this kind of conversation.
No hidden meaning here, but this sure is scary for many adults. What's being implied here is that time seems to be moving really quickly and we're getting older faster than we think. Events that seem like they "just happened" have happened long enough ago for a whole other person to come into existence, grow up, and learn to carry on a conversation. Every time we get reminded of this fact, it can be scary, as you then realize that you are now closer to your death...
9/11 was a terrorist attack in the United States in 2001, on September 11th. Major events such as the assassination of Kennedy, the Moon Landing of Apollo 11 or 9/11 are easily memorable. It is often said that "everyone remembers where they were when they first heard...". In consequence, these events act as milestones in our memory. They are recalled more vividly, and seem more recent. Today this is maybe also topping the Attack on Pearl Harbor happened in 1941.
The title text mentions that Randall is teaching his 8 year old relatives to say the same as in the comic — presumably to the annoyance of his older relatives who will be reminded of the fast passage of time. He does not stop here, but teaches the 14 year old's to say they are born after Toy Story — a major block buster hit from Pixar which came out in 1995. A movie many people will remember fondly and feel just came out the other day... He continues with these scary thoughts by mentioning that Pokémon (1996) came out over a decade ago and that kids born after the big Disney hit movie Aladdin from 1992 will turn 18 next year (i.e. in 2010 a year after this comic was published).
- [First panel: Rob and his nephew are sitting on the ground. Rob is holding a flash-light up to his face.]
- Rob: But they never found the ghost's head!
- Nephew: Lame story, Uncle Rob.
- Rob: And you could do scarier?
- Nephew: Sure.
- [Second panel: Rob has removed the flash-light from his face.]
- Rob: Try me.
- Nephew: 9/11 happened before I was born, yet I'm old enough to have this conversation with you.
- [Third panel: Rob has dropped the flash-light.]
- [Last panel: Rob has curled up and wrapped his arms around himself.]