No chakras, gods or old souls are needed for you to agree to the statement that some aspects of reality are constructed by the human mind (cf. Kant). It explains, for instance, why you perceive what you're sitting on right now as a "chair" rather than the mere collection of atoms and molecules that it's actually made of. Nature outside of the mind has no concept of an object, and no concept of a subject. Acid may help one see reality that way, if one is curious and mentally stable enough to want to.

Disclaimer: NOT intended to be a substitute for professional medical advice, diagnosis, or treatment