In the beginning I think my assumption was a bit like yours - we set a course and deviation is out of the question untill we hit the wall of reality. Jobs not coming in or people losing interest no matter how well the act is performed. Sometimes I think musicians are a hybrid between the actor and the poet. Sometimes we play a role,enterpreting other peoples work,sometimes we deliver the material ourselves. Both of the parts takes some hard effort to fully express the work in question.
But it is a travel that educates you along the way,which I really enjoy - there is more outcome garnered - than what initially appeared to be 😊