"When attempting to enter the business world, you need to learn to be someone else. It is called having a professional identity." - Judith Martin and Nicholas Ivor Martin in "Miss Manners Minds Your Business" (Here you can learn more about the book on Amazon.com)
No, none of us can "be just ourselves" in the workplace. At least, not unless that self has already been packaged into the right persona for that industry, company and department. If there is a change of industry, company and department that professional self will also have to change. There are no exceptions.
Not long ago, I ghostwrote chapters of a book for a Millennial entrepreneur. He had come into the money when he sold his first company. He was all over the media, strutting a brash professional self.
Then he took the position of a chief executive officer of a public company. After a very brief surge, the stock price came tumbling down. It continues its downward trajectory. His persona does not inspire confidence.
On the other hand, I also ghostwrote chapters for and copy edited a book for a political consultant. Her persona is a hybrid of expert and humble listener. She continues to thrive.
As the market for my executive communications services recovers from two recessions in the 21st century so has my persona. It's a seller's market and I have to take charge of the situation, from the get-go. I am the one "interviewing" the prospect to determine if I want to work with that person. And I am the one who is setting the ground rules or terms and conditions of work. Yes, I am expected to say, "You don't seem to have the budget for this." That signals either the prospect indicates there is the budget to pay me or the conversation is over.
How to function in the world world is not intuitive. It is a skill we have to learn. "Miss Manners Minds Your Business" provides many key fundamentals.