It reminds me of a question I've always had. Always been a big fan of "Winnie the Pooh", and you know there is this chapter where Tigger arrives at the forest and doesn't know what he likes to eat... I once asked - "hey, wait a minute, why didn't anyone just ask him what he ate yesterday"...
Seriously though, these things are symbolic, they don't really have to make sense...
It's only when I watch soap operas that I feel they actually insult my intelligence - you know, when some people grow and change and others remain the same age, or when this girl is suddenly older than her cousin, even though she was born several years after him... (and I still watch them...).