The understanding of this sentence is this: those who abandon and betray their own history refer to those who lack respect and recognition for their own history and culture, and those who selectively forget and tamper with their own history. This behavior stems from dissatisfaction with the existing social environment and aims at pursuing short-term interests.

The seriousness of this behavior lies in the fact that history is the basis for a country and a nation to settle down. Abandoning and betraying one's own history means giving up the foundation of self-cognition and self-orientation, which will lead to the confusion and loss of one's own identity, thus affecting the stability and development of the whole society.