The quote "That would be locking the horse after the stable door is gone, a very foolish thing to do" from Patrick O'Brian's "The Far Side of the World" illustrates the futility of taking precautionary measures after damage has already occurred. It suggests that once a situation has unraveled, trying to respond with preventive actions can be both impractical and ineffective, reflecting a common human tendency to react too late.

In this context, the phrase serves as a reminder of the importance of proactive decision-making. It emphasizes the need to address potential issues before they escalate, rather than waiting until it's too late to take meaningful action. Such wisdom prompts readers to consider the implications of their choices and to act with foresight to avoid regrettable outcomes.