By the age of twenty-five (between April 146 and April 147), Marcus had grown disaffected with his studies in jurisprudence, and showed some signs of general malaise. His master, he writes to Fronto, was an unpleasant blowhard, and had made 'a hit at' him: 'It is easy to sit yawning next to a judge, he says, but to "be" a judge is noble work'. Marcus had grown tired of his exercises, of taking positions in imaginary debates. When he criticized the insincerity of conventional language, Fronto took to defend it. In any case, Marcus's formal education was now over. He had kept his teachers on good terms, following them devotedly. It 'affected his health adversely', his biographer writes, to have devoted so much effort to his studies. It was the only thing the biographer could find fault with in Marcus's entire boyhood.