The tortoise doesnt embark on a journey it is not ready to finish. The day you chose this path is the day you chose to be awake.
This proverb emphasis the need for preparation, consistency, perseverance and doggedness. Do not be the type to make decisions at random. Take your time to analyze yourself, observe situations and weigh your options. The moment you arrive at a decision, you must do everything possible to push to the end. It's better you did not start than abscond half way.
Pick up a struggle, horn it through thick and thin till it transforms into a substance. That's the meaning of the proverb.