Three quotes about the difference between working like an amateur and being a professional:
Seth Godin, in This is Marketing:
If you need to be authentic to do your best work, you’re not a professional, you’re a fortunate amateur. Fortunate, because you have a gig where being the person you feel like being in the moment actually helps you move forward.
James Clear, in Atomic Habits:
Professionals know what is important to them and work toward it with purpose; amateurs get pulled off course by the urgencies of life.
Steven Pressfield, in Turning Pro:
The amateur tweets. The pro works.