Your 4-year-old is full of energy, talkative and curious. He’s eager to show you what he can do, and you will both be excited by his accomplishments. He constantly tests his environment and will waffle between feelings of security and insecurity. Your 4-year-old may also be a bossy little tyke who feels the need to be in charge. You will experience emotional highs and lows with this age and each day will be a new challenge — for both of you.