Rather than complaining, be the first-class individual at that job

The most important thing is to first become indispensable wherever you are.  Instead of moaning that a job differs from what you'd like to be doing, he said, become a first-class individual at that job.  This will open the path leading to your next phase in life, during which you should also continue doing your best.  Such continuous efforts are guaranteed to land you a job that you like, that supports your life, and that allows you to contribute to society.