Look at all the lonely people, Paul McCartney wrote. I thought about their plight, through the sadness in his throat. A light switched on before me, as I trundled to my room. I got an idea too, which helped remove the gloom. Schizophrenia! - I shouted. To no one who was there. We’ll give them lots of happy people, inside their heads to share. No more lonely people, and I'm feeling very excited. There’s a party in my head tonight, and everyone’s invited.