Acharya Prashant explains that everything external is considered 'trash' because it is non-essential to our core being. He defines trash as anything that occupies space without utility and whose absence does not diminish our existence. He points out that during deep sleep, we exist without our name, body, or thoughts, proving that these external accumulations are unnecessary burdens. We are often products of external influences like media, society, and upbringing, which makes the internal self seem alien to us. He suggests that our constant questioning about truth and internal richness stems from our deep identification with the external world.