Once while imparting knowledge to the Pandavas and Kauravas in his ashram, Guru Dronacharya asked Duryodhana, the eldest of the Kauravas, to search and find a good person and to bring him along with him to the ashram. Guru Dronacharya then asked Yudhisthira, the eldest of the Pandavas, to find a bad person and get him to the ashram.
Duryodhana set out to find a good person but in spite of searching the entire kingdom he could not find a single good person. He returned back and reported to Guru Dronacharya about his inability to find a good person.
Yudhisthira travelled far and wide of the country searching for a bad person. But he could not locate a single bad person. After several days of search, he too returned back and reported to Guru Dronacharya about his inability to find a bad person.
All the students in the ashram were perplexed with the outcome. They asked, Guru Dronacharya, how come Duryodhana could not find a good person and Yudhisthira could not find a bad person.
Guru Dronacharya then calmly told his students that what we are internally we see that in the world. Duryodhana was filled with pride, jealousy and desire and therefore he was unable to find a good person. Yudhisthira was filled with piety, humility, peace and goodness and therefore he was unable to find a bad person in the same country.
What matters is our outlook if we have a positive outlook we will be able to see light even in the darkest corner of the cave.