Yes, it’s true that working for yourself does give you the complete freedom to choose what work you take on but I feel it goes much deeper than just being your own boss or running your own business.
Working for yourself is when you choose to do work that aligns with your interests, passions, and life goals. It’s not just about making money or gaining status but about getting personal satisfaction and meaning from what you do. You invest your time and energy not just into the business but into yourself as a person, your growth, happiness, and future.
When you reap the rewards and know it is solely by choice and through your actions, that is when feeling of “working for oneself” feels real.
By working for yourself I don't just mean that you are not working under someone else.
Rather, I think that working for yourself refers to those professions where a person is not under someone else, and he has no specific obligations like 8am to 5pm office etc and of course at the same time he likes to do those things as you said, which will be his passions in addition to being his job.
ANd the last, I think working for yourself is only possible when the person loves their work as well as their job.