"A memory is what is left when something happens and does not completely unhappen"

Edward de Bono's quote refers to the principle of a memory being a residue of an event or experience that has actually occurred. Basically, the memory is what stays after an event has actually taken place and can not be undone or eliminated. The idea that something only ends up being a memory if it stops working to "entirely unhappen" suggests that memories are a result of the effect an event has actually had on one's life. While events may be fleeting, memories are more irreversible and act as a record of our experiences. In essence, the quote highlights the significance of memories in shaping who we are as people.