Thoughts are formed through a complex interaction between different regions of the brain orchestrated by the cerebral cortex. The content of our thoughts comes from perceptions, memories, language processing, emotions and other cognitive functions integrated together in consciousness. While we experience thoughts as seamless and instantaneous, they actually involve reusing past memories and learning, combining current perceptions, applying reasoning skills, and building upon ideas through imagination and planning. The physical brain and its development shape the nature and limits of our thinking, though consciousness allows for free will in directing thoughts as well.