The idea is that who you think you are is not actually who you are, but is a construct. This supposedly opens the way for one to be free and construct a “new you.” But this is a classic cult technique also found in New Age and other esoteric teachings. Keep in mind that Erhard, the founder of Landmark (originally est), had been involved in Scientology, one of the most quintessential cults in existence and masters at mind manipulation, as well as being influenced by Zen Buddhism.