Acharya Prashant explains that identifying a true Guru is similar to knowing if the sun has risen. One does not need to stare directly at the sun to confirm its presence; doing so would only lead to blindness. Instead, the proof of the sun's rising is that the world becomes visible and one stops stumbling in the darkness. Similarly, the authenticity of a Guru should not be judged by investigating the Guru's person or status, but by observing the change in one's own life. If your vision has cleared, your discernment between the real and the unreal has increased, and you no longer stumble in the world, then the Guru is true. The word Guru signifies the one who brings light into darkness, and the only valid evidence of that light is the clarity in the seeker's own eyes.