The word 忘掉 is formed by combining the character 忘, which means "to forget", with the character 掉, which literally means "to fall" or "to drop". In this pairing, 掉 does not retain its primary physical meaning but instead acts as a complement that adds a sense of thoroughness, completion, or finality to the action. Thus, 忘掉 evolves to mean not just "to forget", but "to forget completely", "to dismiss from mind", or "to get rid of by forgetting", where the second character reinforces and extends the conclusive nature of the mental action implied by the first.