Copernicus made dramatic changes in astronomy and science. Nicolas Copernicus had a lot of work to do, yet he managed to keep on learning and studying every day. So practically, Copernicus was the master Jack of all trades. Copernicus was the master of whatever he did.
Nicolas Copernicus showed his friends an important manuscript that he was writing and described the theory he was writing to his friends. At that time, some books he wrote were rumored to exist to the public. Later on, Copernicus was persuaded by his friends to publish his manuscript.
Copernicus developed internal bleeding and paralysis in 1543 just before the manuscript was fully published, and died at the age of 70 years old just when the manuscript was published.