Most of the time you need a plan B. A safety net. A fallback position.
But sometimes you need to make quitting more unpleasant than fighting to the end.
It is easier to persevere when you don’t have options.
For example, tell everybody about your grand dream. Knowing that other people are watching will motivate you. It gives you something to live up to.
By telling the world in advance of your mission, you’ll cut off your retreat.
Sink or swim?