The straight answer to that objection is do something about it. We may have work-related skills that will help us become self-employed. In order to do this, we also need some basic business skills like finding customers, bookkeeping and filling in tax forms. There are many ways of picking up such skills from books or courses for people who want to set up a business. We may find a coach or a mentor useful. All we need is to find a way of learning the necessary skills.
We don’t need to know it all to succeed
We do not need to know it all because we can work with those who know more about certain things than we do ourselves. For example, a few years ago I visited an English class and met someone who had run their own business for many years. Their education had been disrupted by the things going on in the world when they were a child and they had not developed the sort of reading and writing skills many of us take for granted. They managed to run their business by finding a secretary who could do the paperwork for them.
Actually in the business arena it is often not possible for one person to do all the tasks necessary to be successful. There simply is too much for one person to do. They have to gather a team of people with different strengths, different abilities, different specialised knowledge in order to succeed. There are many stories of how when someone has taken on a helper or team member it has been so much easier to succeed. This is because more of the tasks that need to be done can be done, and can be done well.