Whatever your motivations to persist may be, they will prove useful. It will be easier to persist if you select a field of business that you like, as opposed to pursuing something just for the money. Focusing on presenting solutions, not on selling products and services. Usually no one will see that things get done but yourself. Regardless of what business you're in, marketing is the tool used to present the solutions that your products and services offer to the rest of the world.
Marketing is a skill.
Like any other skill, it can be developed through knowledge and practice. As many employees of large corporations have been discovering to their dismay, even seniority doesn't always guarantee job security. I consider important. If followed, these keys can help you leave the rat race, too.