I keep returning to the idea of focus. In order to be successful you must focus.
With art, the artist must focus in order to establish a consistent theme. This is not only for the audience, but also for this artist, because without this consistency it’s not possible to gain the deep observations from focusing in one area.
With a career it is the same. You cannot do many jobs and be successful. You must choose one job and focus. It is only with this focus in your career that you can achieve the knowledge and experience to be successful professionally. If you try to do Many jobs you’ll be mediocre at all of them. If you focus on one job you have a greater chance of success.
It is the same with your identity. If you try to live many lives, you will be mediocre at all of them. In order to be successful you must choose one life to live. It is only by focusing on one identity that you can achieve the deep insights of that one life.
If you try to live many lives at once it would be like walking into a movie and walking out after the first 10 minutes never getting to see the middle or the end or how the characters develop. It will be like only reading the introduction of the book or only listening to the preamble of a symphony. Or when meeting someone it would be like only talking to them for one minute and then never seeing them again.