The "split brain": there are two of you in yourself - video from CGP Grey.
The video presents what happens when the connections between the left and right sides of your brain are cut.
Spoiler alert: it suggests that each side act independently of each other. And supposes that in your body, there are two intelligences / consciences / people / something that we have no name for.
The video also very mildly questions whether we have free will - but only in one sentence as a reference for another video essay (which I don't think he has released yet).
At the end, CGP Grey recommends another video from another cannel, Kurzgesagt. I recommend the viewing of that video, too.
(Also, I've been subscribed to both CGP Grey and Kurzgesagt for years. For a lay person, I find their method of describing science very easy to understand.)
EDIT: more scientific info released in the last few days by SciShow Pysche YouTube channel:
busy day, so haven't watched the videos yet, I have observed different parts of peoples minds independent of other parts. I mean minds, not brains. Consider the brain as a bunch of ingredients, sugar, water, flour, eggs. The brain is the raw material or building blocks of the mind, using different parts of it can create a variety of "minds" for want of a better word. I have 7. They do not have to agree with each other, I can switch from one to another to consider a situation from another perspective. I play devils advocate really well and can put up a strong argument to make someone prove their point, even when I agree with them. Bad Rugglesby.