The mental state you are referring to is commonly known as "euphoria." Euphoria is a feeling of intense joy, happiness, or excitement that can occur suddenly and is often accompanied by a sense of well-being and exhilaration. It can be triggered by various factors such as positive life events, thrilling experiences, accomplishments, or even certain substances (e.g., drugs or endorphins released during physical activities). Euphoria is a natural and temporary emotional state, and it can vary in intensity and duration from person to person and situation to situation.