my last boss is 83, been practicing law for 55 years and still works 40 hours a week. he's very well-off financially and could do nothing but play golf if he wanted to, but he loves to work...absolutely loves it...and he's a very happy person. some people like to work and a lot of people don't get that. i don't have that work ethic/obsession, but i'm not going to disparage people who do.
My mom works for a company owned by three partners and they are exactly like this. IMO, there are two key things that must exist for someone to be like this. They don't necessarily have to both exist but at least one.
1. Have a passion for what you're doing. Not everyone is able to love something or have a passion for something that circumstances have worked in a such a way that they are able to also do that for a living. The average person does something for a living because not because they have a passion for it, but because it pays the bills.
2. Be the owner of the business or have some form of financial interest (other than a regular employee paycheck) in the company.
A guy I used to run with couldn't understand why I didn't "love" going to work. Since I chose to go to college and become an accountant. I'm obviously doing what I wanted to do.
On some level he's right. But on another level he's wrong. Though I'm doing something that (in the beginning) I enjoyed. "Life" and a lot of things I didn't know that comes along with the job, has now pushed me to burn out in this field. Things that if I somehow could have known beforehand would more than likely have made me think twice about going into what I went into.
He on the other hand, went into the medical field, which he enjoys. But also is in a unique situation (within his field) where he gets bank rolled with Christmas bonuses that equals half my salary and quarterly bonuses that are roughly 1/4 my wife's salary. He makes well above the average physician assistants pay. So he loves his job more because element #2 exist than #1.