Lin Yi immersed his mind, beginning to comprehend his True Self. In the information given by the Pill Immortal Master, there weren't many details on how to comprehend, because each cultivator's situation was different. Comprehending the True Self naturally revolves around oneself.
The comprehension of others is merely their self and not their actual self. It wouldn't help you; on the contrary, too much exposure could confuse you, imposing another false self on the already challenging comprehension journey.
On Earth, whether it's Buddhism or Taoism, there are teachings about comprehending the True Self, dispelling the false self to see the True Self, returning to one's nature. Taoism calls this "Returning to Simplicity," while Buddhism phrases it as "Removing Illusions to Restore Truth." Nevertheless, the core meaning remains the same.