According to the Epic Mahabharat, Lord Parashurama was very strict and took swear that he would not give his knowledge to any other caste except brahmins. Drona Acharya refused to give knowledge to Karna who was a Kshatriya. Afterward, Karna lied to Parashurama that he was a brahmin and wanted to take knowledge from him. Parashurama decided to give his knowledge to Karna without knowing that he was a Kshatriya. When Parashurama had known that Karna lied to him, he cursed Karna that "Karna will forget all his knowledge when he will need it most".