Whilst routine work and life is quite important sometimes, in the long run you end up living within a set parameter and become a dull person with hopes and fantasies of doing many other things and activities if you weren't at work. The sad thing is all of us are bound by our monthly paychecks and are afraid to tough it out for a better future. Who knows you might win and u might fail too right?! Scary.
About building someone's dreams by working for them, well, they too are giving you a chance to build your own dream by giving you a salary and a job for experience. But most times you'll end up with the money but without the opportunity as the train has long ago, left the station. You would be less inclined to start a new venture but nevertheless it is never too late to be a grandpa boomer.
Don't let what you have learnt or have been taught be the only guide in shaping who you are. It's is compelling to be yourself and follow your heart. We don't need to meet another me or I everywhere we go.
Why it's important to living a fulfilling life? It's not so much about you when you are dead and gone. It's about the people you leave behind. Imagine if you lived a stressful and unhappy life, your next of kin would feel like they never did enough for you and regrets will fill up the whole mind bubble and someone else is gonna be depressed. This will just turn into a vicious cycle and everyone will be depressed until one day they are strong enough to decide that it's enough and a change is mandatory.
If you hate your job, find a new one. If you despise your partner and there is no return, then don't return. If you are ill, go to the doctor! If you need to lose weight, go exercise. Learn from those who failed and follow those who are successful. Don't deny yourself from learning new things and be curious to take on new adventures. You have one life and don't waste it.