In the practice of music, you have to learn how to critique yourself. This comes in handy in so many parts of life.
Back in the day, the record industry had a role called the "A&R" representative. When I was a kid, the A&R rep was the one who offered the band a record contract. But the history gets wilder.
"A&R" stood for "Artist and Repertoire". The A&R would book a record session, choosing the Artist, and then choosing the Repertoire – telling them what to play.
Before Dylan and The Beatles, there was no expectation or even possibility that artists would choose their own material. Performing artists were seen – at best – as vessels through whom the composition would flow. Less charitably, they were seen as monkeys, who couldn't be trusted to make decisions.
Dylan changed this, somehow scoring one hit record after another with his nasal honk of a voice. The Beatles changed it with their hits, at first by choosing material the A&R reps would never have considered, later by writing oddball songs that suited them perfectly.
Nobody to this day really understands what makes one record hit and another flop. But record companies were forced to admit that performing artists had a better intuition about it.
As the Bible verse says, every day brings both a blessing and a curse. Artists could now choose; but choosing is a terrible responsibility.
A musician has to be honest. When you practice your instrument, you have to learn to listen to yourself critically, and to know your limitations.
As a human being, you are in charge of a work of art called 'your life'. You're the producer, the writer, the costume designer.
You are your own A&R rep. Produce yourself.