Because words only exist on the physical plane we inhabit as humans with physical bodies. There are no words that can convey the experience of an encounter with one's true Self, upper case, as opposed to one's self in this world, lower case. It can't be boxed in by words humans use, can't be described through mere words but must be experienced to be understood. This world we see around us is mere illusion, something of no value to Self and thus our bodies, the 'world' we know and mistake as real isn't 'real' on higher planes, such as where Self is met.