Even Clarke took decades to learn the cornet

I was cornet soloist with Gilmore at the age of twenty-four, held the same position with Sousa at twenty-five and did not really know how to play the cornet correctly until I was thirty-five! Since then it has never been a task to play my chosen instrument all day long.

Herbert L. Clarke, How I Became a Cornetist  (BrassMusician.com: 2011) (orig. pub. 1934), Ch. 24