Here is an incident that happened to me at my old startup. This literally gave me a wake-up call that shattered my "PM is mini-CEO" idea that all my mentors had told me about.
During a heated product roadmap + prio meeting, the actual CEO, berated me a lot and made fun of my "vision" doc. He called my user research "overrated guesswork" and dismissed the Jira workflow as "a waste of time". He then laughed at my definition of product-market fit and all the metrics I had decided. Mind you, I was the first PM hire at this startup at that time and I used to report directly to the CEO.
When I tried to defend myself with data, he accused me of cherry-picking stats and that I manipulated the data. He then demanded that I learn to code and make use of my degree. I studied Computer Science in college btw. When I asked Why? he said that I needed to create a working prototype by next week. This was abviously a joke but he had made a point, he thought that I was not doing real work.
As I left the meeting room, I realised two things: I'm not nearly as important as I thought, and this job isn't about changing the world, it's about surviving the brutal reality of business. It was a harsh reminder that in the end, the CEO and not me, calls the shots.