You can't judge a book by its cover

The saying "You can't judge a book by its cover" is a proverbial expression that cautions against forming opinions or making assumptions about something or someone based solely on superficial appearances. It suggests that external appearances or first impressions may be deceiving and do not necessarily reflect the true nature or quality of the object or person being evaluated. This idiom originates from the literal interpretation of not being able to accurately assess the content or value of a book by merely examining its cover without delving into its contents.
In a broader sense, "You can't judge a book by its cover" advises against snap judgments and encourages deeper examination or exploration before forming conclusions. It underscores the importance of looking beyond surface-level attributes and taking the time to understand the complexities and nuances of a situation or individual. By refraining from hasty judgments based on outward appearances, one can avoid misunderstandings, prejudice, and missed opportunities for meaningful connections or experiences. Essentially, this expression promotes open-mindedness, empathy, and a willingness to look beneath the surface to uncover the true essence or worth of something or someone.