Workers were required to stay six months, and even then permission to quit was not always granted. The factory held the first two months of every worker's pay; leaving without approval meant losing that money and starting over somewhere else. That was a fact of factory life you couldn't know from the outside: Getting into a factory was easy. The hard part was getting out.
A person cannot grow up through happiness. Happiness makes a person shallow. It is only through suffering that we grow up, transform, and come to a better understanding of life.