In the following excerpt from Roald Dahl's Boy, he's left public school at 18 to take a job with Shell Oil company. He is taking their internal training courses and is learning the business.
...[E]very morning, six days a week, Saturdays included, I would dress neatly in a sombre grey suit, have breakfast at seven forty-five and then, with a brown trilby on my head and a furled umbrella in my hand, I would board the eight-fifteen train to London together with a swarm of other equally sombre-suited businessmen. I found it easy to fall into their pattern. We were all very serious and dignified gents taking the train to our offices in the City of London where each of us, so we thought, was engaged in high finance and other enormously important matters. Most of my companions wore hard bowler hats, and a few like me wore soft trilbys, but not one of us on that train in the year of 1934 went bareheaded. It wasn't done. And none of us, even on the sunniest of days, went without his furled umbrella. The umbrella was our badge of office. We felt naked without it. Also it was a sign of respectability. Road-menders and plumbers never went to work with umbrellas. Businessmen did.
I enjoyed it. I really did. I began to realise how simple life could be if one had a regular routine to follow with fixed hours and a fixed salary and very little original thinking to do. The life of a writer is absolute hell compared with the life of a businessman. The writer has to force himself to work. He has to make his own hours and if he doesn't go to his desk at all there is nobody to scold him. If he is a writer of fiction he lives in a world of fear. Each new day demands new ideas and he can never be sure whether he is going to come up with them or not. Two hours of writing fiction leaves this particular writer absolutely drained. For those two hours he has been miles away, he has been somewhere else, in a different place with totally different people, and the effort of swimming back into normal surroundings is very great. It is almost a shock. The writer walks out of his workroom in a daze. He wants a drink. He needs it. It happens to be a fact that nearly every writer of fiction in the world drinks more whiskey than is good for him. He does it to give himself faith, hope, and courage. A person is a fool to become a writer. His only compensation is absolute freedom. He has no master except his own soul, and that, I am sure, is why he does it.