"Why is my baby crying?" "What was going on in that head?" Have you ever considered that your baby grows not only physically, but also mentally from birth? Did you know that during the first year of life your baby can suddenly suddenly discover something new in his or her baby world ?! Such as contours or colors. Do you think it is strange that your baby becomes weepy, when his or her familiar environment is constantly being overthrown? This book shows you what's going on in your baby's head. It goes by leaps and bounds. The leaps in this mental development are identifiable and recognizable. Around five weeks, another around eight weeks, then around twelve weeks and so on. At increasing intervals. You learn to understand your baby. You learn to recognize the jumps by the behavior of the baby. You learn how to respond to it. You will learn to see when your baby is open to learning new things! This book tells you something new, something important! They are trailblazers, Hetty van de Rijt and Frans Plooij, the authors of the bestseller Oops, I'm growing! Their book, which everyone knows, has been in the top ten best-selling non-fiction for years. While translation after translation abroad followed, Van de Rijt and Plooij continued their research into the mental development of babies. Now there is a new edition, which has been greatly expanded by two chapters and now describes the first twenty months of a baby. Oops, I'm growing! is undoubtedly one of Dutch business cards. More than 370,000 copies were sold in the Netherlands and Belgium, and the 'jump phenomenon' discovered by Van de Rijt and Plooij was also very popular internationally. Oops, I'm growing! is now being released worldwide, from America to Japan. The extended edition covers two 'new' major developmental leaps, namely those around 64 and around 75 weeks. During this period, a baby 'discovers' values ​​and norms, rules and principles and budding self-understanding. Parents often find these periods in the second year of life difficult because they are often accompanied by quarrels and conflicts. It is not without reason that many parents speak of toddler puberty. The success of Oops, I'm growing! lies mainly in the fact that the book offers young parents support and help in the difficult times they go through with their babies. Van de Rijt and Plooij call this the periods of the three H's: Pendantiness, Tearfulness and Moodiness. With every jump, the baby gains new perception and learning ability. The 'jumps' introduced by the authors have been researched and confirmed internationally. English, Spanish and Swedish research found mental jumps at the same ages as in Oops, I'm growing! described.