Core activity, as the theoretical origin of Serious Leisure Perspective (SLP), is the cornerstone of all human activity definitions for Stebbins. He described serious leisure as a combination of specific activity content and action sequences that embody human agency, thereby expanding the entire family tree of all human activities in SLP. However, it has also attracted many criticisms from the scholars due to its assertiveness and reductionist tendency. Although core activity has some objective practicality, the three presuppositions of the actor, content-form, and causal relationship have turned it into an ideal type, thus losing its flexibility to explain all specific human activities. In fact, core activity are more similar to a certain “meaningful form”, which on the one hand, at the macro level, reflects the collective accumulation of human cultural history in the symbols of activity forms, and on the other hand, at the micro level, it also reflects the individual accumulation of similar activities by different individuals. These two dimensions are key to addressing the reductionist tendencies inherent in the concept of the core activity.