Our minds are not one but many
Two experiences that seem to me to show that our minds are not one but many: first of all, when I'm playing tennis, and am receiving serve, and the serve hits the net, I find that my body still leaps to the left or the right, even though my conscious mind already knows that the ball has hit the net. In other words, one bit of my mind sends a signal to my motor system to jump left or right, and then it realizes that the ball is actually going to hit the net - but the signal has already gone out, so my body jumps to the right anyway. This shows the delay between a mental signal and the physical action - only a few milli-seconds, but you can see it.
This has relevance to Benjamin Libet's famous experiments on free will, in which you can see brain activity a few milliseconds before a person moves their finger. Libet has taken this as evidence that our intentions are unconscious and therefore not free or voluntary - and you'd be amazed to what extent neuroscientists have used this one experiment to dismiss the whole idea of humans possessing free will. How eager they are to make us automatons! But it seems to me the experiment could be explained simply as the time-lag between a mental intention and the physical result - just like when I jump to the right despite knowing the ball has already hit the net.
Nonetheless, I agree with neuroscientists like David Eagleman that our minds do have an unconscious, which can know things that our conscious mind has forgotten. For example, I sometimes find, when I'm hungover for example, that I can't remember my PIN code. But my unconscious mind will, of course, remember it, if I just trust its intuitions. The same is true when I forget a website password. I also find that I will sometimes be on the Tube, and the Tube will arrive at a station. My conscious mind will try to remember which side of the Tube the platform is, while my unconscious mind will already know, if I trust it.
[Pic by Dianne Krauss from Wiki Commons]