Mental health is an important topic to understand, and the Brainpower series (4 titles) helps readers navigate their emotions. Here, three reassuring chapters walk readers through what it means to feel sad and how it affects our brain, differentiating between sadness and depression. Diagrams of the brain show the different areas scientists believe are involved in processing sadness (the amygdala and hippocampus) and detecting pain (the vagus nerve and anterior cingulate cortex). The text also explores why grief is exhausting and the benefits of having “a good cry.” Importantly, the final chapter lets readers know that it’s OK and normal to feel sad sometimes, and it offers advice for dealing with this feeling, such as practicing mindfulness and spending time with others. Appended with helpful “Goals and Tools” for managing emotions.