burn one's bridges/boats, to

burn one's bridges

 (behind one)
1. Lit. to cutoff the way back to where you came from, making it impossible to retreat. The army, which had burned its bridges behind it, couldn't go back. By blowing up the road, the spies had burned their bridges behind them.
2. Fig. to act unpleasantly in a situation that you are leaving, ensuring that you'll never be welcome to return. If you get mad and quit your job, you'll be burning your bridges behind you. No sense burning your bridges. Be polite and leave quietly.
3. Fig. to make decisions that cannot be changed in the future. If you drop out of school now, you'll be burning your bridges behind you. You're too young to burn your bridges that way.
See also: bridge, burn

burn (one's) bridges

To eliminate the possibility of return or retreat.
See also: bridge, burn

burn one's bridges/boats, to

To commit oneself to an irreversible course of action, without possibility of backing down. The expression comes from ancient military history, when soldiers crossing a river literally burned the bridge or boats they had used in order to cut off the possibility of retreat. A cliché by the nineteenth century, the expression has invited a number of humorous twists, such as “Never burn your bridges till you come to them” (Stanley Walker, 1941). See also cross the Rubicon.
See also: bridge, burn