The Roman Republic passed a law forbidding any General and his army from crossing the Rubicon, a small river in northern Italy, which formed a natural border that defined the frontier boundary of the country. Upon reaching the Rubicon, the army would have to disband into smaller units, each one going to their individual base camps. Crossing the Rubicon without following this law was considered an act of war.
In 49 BC, Julius Caesar found out that the ruling Governors, concerned with his increasing popularity with the troops, were contemplating executing him upon his return to Rome. Julius Caesar made the decision to cross the Rubicon with his army and take Rome by force. The legend has it that he shouted the words “the die is cast” while crossing the river. https://en.wikipedia.org/wiki/Rubicon
The term “Crossing the Rubicon” is used as a metaphor in describing a point of no return by committing a deliberate, permanent and irreversible action. Each individual wishing to have the “moonshot” either on a personal level, or as part of a team, must make the decision to cross their own Rubicon and fully commit in order to achieve their goals and objectives.