Today I read a story someone posted online about a guy who has worked his whole life, then was unemployed:
"One family member worked for the same company for 20 years and was laid off. He was willing to work at any job but could not find work for 15 months. It had a dramatic effect on him. After finding work, two years later the company he was with went under and he was out of work for a year. He is an upper level accountant and his experience is in a specialized field. He could not even get a job as an entry level accountant because he was 'over-qualified'"
This story is such a reminder that working many years for the same company could be very dangerous. Typically you either go up along the way, or go down and be fired/laid off. There is no safe harbor in a company where you could rest forever.
That, and the office politics, are enough to drive a self-motivated person to start his/her own business and be successful with it.