The phrase "like a kid in a candy store" is an idiomatic expression that means someone is extremely excited, enthusiastic or eager about something. It's used to describe a person who is overjoyed and thrilled by the prospect of doing or having something they love. The image it evokes is of a child experiencing pure joy and excitement when entering a candy store - filled with all sorts of colorful, sweet treats that they can't wait to explore and indulge in. So, if someone says you are acting "like a kid in a candy store," they mean that you are very enthusiastic about something!