The human body finds it knows things, senses things, and attributes this to all manner of reasons because its dealing basically only with what it has perceived and learned in school and from its immediate family. So there are incidences where a Star Child has lived its entire life and the human body has never become aware of the true nature of the incarnated entity, or maybe not even be aware of reincarnation as a concept. Other Star Children are aware almost from birth of their true nature. In many cases, the incarnating spirit allows the body to not be troubled until the time comes for action and then intrudes upon the body to get in sync. Often this is very stressful for the human body.
Illness can prevail, and a lot of anxiety.
Thus often the human is given an out, so unless it is necessary for the human to be in sync, the human is allowed to blithely go along in ignorance.