I think it was the preparation time, not the cooking time. You can prepare a vegetable soup from raw vegetables in less than 15 minutes. With some training you can do that in 5 minutes. You'll need an extra 30 minutes simmering though but no more work after preparation unless you want it mixed. You really can't overcook a vegetable soup. You can even keep it a couple of days in the pan without it getting sour. It's a hassle free meal.

But you are right, the truth lies between 15 minutes and an hour.