Back in 1980 I went on a trip to the US with a group of fellow Barry Manilow fans. The flight home out of Las Vegas was very early so one of the ladies asked the receptionist if they could arrange to knock us all up at 04.00. The look on his face was priceless.
Over here in the UK, during the Industrial Revolution people were actually employed to knock on people's doors to get them up in time for work, a form of human alarm clock. Hence the phrase was born. As it happens I actually caught mention of it as a job at the tail end of a quiz show last night before we settled down to watch the Bond film, which brought this to mind.
In the States, to be 'knocked up' was getting someone pregnant. As there were about 50 of us, ranging from girls like me, barely 20 at the time, to women of a more mature age, as I am now, I can imagine the thoughts running through his mind, until we cleared the meaning up.
"I meant," said Ipslore bitterly, "what is there in this world that truly makes living worthwhile?"
Death thought about it.
"Cats," he said eventually. "Cats are nice."
Terry Pratchett, Sourcery