Leslie Patricelli's 'Baby Happy, Baby Sad' is a quintessential board book for introducing emotional literacy to the youngest readers. Through its iconic, expressive baby character and minimal text, the book directly illustrates the contrast between happy and sad moments in a baby's day. It handles sensitive topics like sadness and frustration with a gentle, normalizing tone, showing that all feelings are a natural part of life. The emotional arc is simple and reassuring, moving between contrasting states without dwelling on negativity. This book is specifically for toddlers and preschoolers who are beginning to identify and express their own emotions. A parent would reach for this when their child is experiencing big feelings, or when they want to start conversations about emotions. No specific preparation is needed, as the book is straightforward and visually driven. Younger toddlers will enjoy pointing at the baby's expressions, while older preschoolers can begin to articulate why the baby might feel a certain way. Its simplicity and directness make it stand out as an excellent first book on emotions.