How does Okonkwo work to acheive greatness as defined by his culture?

In his youth, he became famous when he defeated Amilinze the Cat, a great wrester. He is a formidable man, stern and intimidating in appearance; when angry, he stammers. Okonkwo did not inherit anything, everything he has he has earned himself.  He had to start out as a sharecropper for a rich man named Nwakibie. Nwakibie was generous, but the first year Okonkwo planted was the worst planting year in Umuofia's living memory. Okonkwo, with superhuman determination, survived.