It is unacceptable to skip appointments.
Andy had an appointment scheduled with his doctor to help fix his meth addiction at 2, but that's usually when he does his meth.
Andy has to pick between going to his appointment and doing meth.
Andy goes to his appointment because he recognizes that he has a problem.
Andy decides to do meth instead of going to the appointment.
Andy's addiction becomes less of a problem, and his doctor is happy that Andy is motivated to get over his problem.
Andy's problem becomes worse, and he wasted his doctor's time.