Discuss the Two Biggest Difficulties for Locke's Theory That Personal

Discuss the two biggest difficulties for Locke's theory that personal identity is based on memories of one's former experiences. If it is memory that unites different "person stages" of the past with the person existing in the present stage into a single entity, then how does forgetting, or even remembering inaccurately, affect the self? If you no longer remember falling off your bike at eight (or falsely remember that it was someone else falling), does that mean that stage of your history is no longer part of who you are today?