Creativity is a complex phenomenon. This paper highlights emotion mediates creativity development in various situations that happen in our everyday life. Particularly, three important emotional expressions of ‘Ah!’(wonder/curiosity), ‘HaHa!’(laughter/fun), and ‘Aha!’(discovery/inspiration) are focused on in the theoretical discussion that helps to explore links between emotion, creativity, teaching, and learning in STEM education. The interplay between experiences of ‘Ah!’, ‘HaHa!’ and ‘Aha!’ forms a new tool of ‘Ah!-HaHa!-Aha!’ that can be used to foster a creative climate. Furthermore, a pedagogical model is proposed for developing creativity in STEM education. The model integrates with ‘Ah!-HaHa!-Aha!’, Inquiry and Problem-Based Learning, Playful Learning, and Teaching for Deeper Learning in one framework. It regards everyday life as the learning context and underpins a systematic perspective to facilitate creativity in STEM education. This also provides STEM teachers with various methods and strategies to develop students’ creativity in their daily pedagogical practice.