Characters
Sorry about not ringing back, the whole two names concept was too much for my flatmate's pea-sized intellect.
— William • Notting Hill
Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker apologises for not calling back, then delivers the excuse with a sarcastic sting: the idea of two names was apparently beyond a flatmate's tiny intellect. The politeness of the apology is undercut by the insult, blaming the missed contact on someone else's supposed stupidity.
Context reviewed