You can also have an exciting work that fits your interests because life is short and it is better to enjoy most of your work hours.

And once your job becomes non-interesting, what do you do? Quit? How many times?

I expect some excitement from my work but in the end it is just work. I work 8 hours and they pay me for that. I think having that personal attachment to your work and expecting more from it leads to early burn out when things are not going great

If you job becomes non interesting you need to take actions to make it interesting again. Perhaps some change of projects, of responsibilities, of technologies, of scenery. If it’s not possible or it doesn’t work you will have find another interesting job indeed. You may have to do that a few times during a career but I don’t think you should switch every second year.

It’s true that if you love your job, it may be hard when it’s not going great.