Hrm, it's interesting...
Might be because they are so open to suggestions, they listen before looking.
My job basically consists of playing with children and telling them huuuuuge lies ('s true!) and you can just see that moment of doubt in some of the older kids' eyes, whereas the younger ones believe every single word you say. And the 'grown' ones, of course, dismiss the lie immedeately. That's so boring ^^
Same with drunks, I'd guess. They're in a state where they are far more suggestible, so it's easier to make them listen. And they -do- listen! I've had some of the most intelligent conversations with drunks, and it makes me feel a little guilty for not being as drunk as them, 'cause then I might start listening to them as well. Eh!
Kids and drunks are great, really.
~Moi