单项选择题

My new home was a long way from the center of London but it was becoming essential to find a job, so finally I spent a whole morning getting to town and putting my name down to be considered by London Transport for a job on the tube. They were looking for guards, not drivers. This suited me. I couldn’t drive a car but thought that I could probably guard a train, and perhaps continue to write my poems between stations. The writers Keats and Chekhov had been doctors. T.S. Eliot had worked in a band and Wallace Stevens for an insurance company. I would be a tube guard. I could see myself being cheerful, useful, a good man in a crisis. Obviously I would be overqualified hut I was willing to forget about that in return for a steady income and travel privileges—those being particularly welcome to someone living a long way from the city center.
The next day I sat down, with almost a hundred other candidates, for the intelligence test. I must have done all right because after half an hour’s wait I was sent into another room for a psychological test. This time there were only about fifty candidates. The examiner sat at a desk. You were signaled forward to occupy the seat opposite him when the previous occupant had been dismissed after a greater or shorter time. Obviously the long interviews were the more successful ones. Some of the interviews were as long as five minutes. Mine was the only one that lasted a minute and a half.
I can remember the questions now: "Why did you leave your last job" "Why did you leave your job before that" "And the one before that" I can’t recall my answers except that they were short at first and grew progressively shorter. His closing statement, I thought, revealed a lack of sensitivity which helped to explain why as a psychologist, he had risen no higher than the underground railway. "You have failed the psychological test and we are unable to offer you a position."
Failing to get that job was my low point. Or so I thought, believing that the work was easy. Actually, such jobs—being a postman is another one I still desire—demand exactly the sort of elementary yet responsible awareness that the habitual dreamer is least qualified to give. But I was still far short of full self-understanding. I was also short of cash.
What does the writer realize now that he did not realize then