Lack of taking massive action

I’m confused about the model and massive action. For example, if I choose to think that my entry level job is the best, I likely won’t want to change it/move up the ladder. I will work in my current position for the next 40 years and be happy about it. How is that different from stagnation/no development/not growing? If I’m happy where I am, why would I choose to try anything new? I feel like I would be in the same place all my life and although be happy about it, I might have some financial problems sending kids to college or in retirement.