Well perhaps im not completely brainless but this is how we should approach thinking.
We think we know things but why do we think we do?
Who said it was right and why should we believe them?
After all no-one really even knows how our brain procesess data and how it makes calculations.
We have constructed theories of how thinking occurs but most of it remains a mystery.
So here is an interesting, high quality, FREE Online Course that examines these questions and highligts how we think our thinking works.
Also here is a previous piece on this particular Free Learning Platform where you can easily access this course and MANY more.