and careers were much simpler in the mid 20th century when the world changed much more slowly. People chose a career, and followed it for their entire working life. Today's world is seeing dramatic changes though, every year.
If you want secure employment, you need to stay in tune with today's world, anticipate the future and be capable of adapting how you work to new opportunities as they emerge. This may mean embracing self employment more than you might have anticipated; or retraining and moving sideways on your career path as the opportunity to move forwards simply disappears. Those who embrace the reality of a rapidly changing world will be those who have employment security.