The sudden flashback to his wartime experiences left him momentarily disoriented.

flashback 由 flash（闪光、闪现）和 back（回、向后）组成，字面意思是"闪回"，指突然回忆起过去的经历或场景。在心理学和文学中，flashback 特指"回忆片段"或"倒叙"。