The greatest epics of the Indian soil, the Ramayana and the Mahabharata, have been placed in this world with a purpose (well, several purposes). Each scene, each action, is a lesson to those who wish to learn. If you have heard the stories at least once, they have this ability to stay in your mind and emerge at a seemingly insignificant time.
One of the stories that I find quite appealing is Karna’s encounter with Parashuram to acquire a skill that no Kshattriya could learn, that would make him one of the most powerful of them all. However he had to tell a lie to gain his end, and, when Parashuram came to know of it, was punished.
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Karna was keen to acquire the Brahmastra mantra from the great teacher Parashuram. However, he knew that Parashuram gave instructions to Brahmins (the priestly tribe) only. So he disguised as a Brahmin and beseeched Parashuram to accept him as a shishya(disciple). Parashuram accepted him as such and started giving him instructions. One day when Parashuram was resting with his head in Karnas lap, it so happened that a bee stung Karna on the lower portion of his thigh. It was very painful and he started bleeding. However, fearing that if he moved his legs, he would awaken Parashuram, he did not move at all and continued to suffer. When Parashuram woke up, he saw Karna bleeding. He asked, Son, tell me truthfully who you are? A Brahmin cannot suffer so much physical pain. Only a kshattriya (the warrior tribe) can endure so much discomfort. Karna was obliged to disclose his identity. Parashuram was greatly annoyed because he was a sworn enemy of Kshattriyas. He therefore cursed Karna that as he had learnt through deceit, he shall forget the vidya (skill) which Parashuram had taught him, at a crucial juncture.
Parashuram’s curse was to prove Karna’s undoing. At the Kurukshetra battle, when face to face with Arjuna, Karna forgot the Brahmastra mantra taught to him by Parshuram. The wheels of his chariot sank in soft earth and he was immobilised. At that time, Arjuna defeated him.