What is let bygones be bygones?

The phrase "let bygones be bygones" is an idiomatic expression used to suggest that people should forget about past disagreements or grievances and move on. Essentially, it means to forgive and forget, allowing past conflicts to be left behind in order to focus on the present and future. The expression encourages reconciliation and suggests that dwelling on past issues can be counterproductive to maintaining healthy relationships.

Historically, the expression dates back to the 16th century, with the word "bygones" meaning things that have gone by or past events. Over time, it has become a common phrase in English-speaking cultures, used in both personal relationships and in broader contexts such as diplomacy and conflict resolution.

In practice, letting bygones be bygones involves an intentional decision to release negative emotions and not hold grudges, allowing for healing and the possibility of mending or improving relationships.