"No matter how many mistakes you make or how slow your progress, you are still way ahead of everyone who isn't trying" - Tony Robbins
The way I see this is progress is still a progress regardless how slow that progress may be. Doing something that we feel passionate about, doing something that we enjoy every day is very important, even if we doing it part-time. What's important is not how fast, but getting started and following through on our goals and commitments. Who cares if we make mistakes, as long as we are learning and progressing forward. The only sure way not to make any mistakes is not to do anything and take no action. Remember, when we take no action, we see no results.