How people remember their past lives.

I think you want to recall your past life. Only very few people (especially children till the age of 5-6 years) remember their past lives to various degrees. Majority of us have no remembrance/recollection of past lives. Some people get spontaneous recall upon visiting certain places, usually in a foreign country away from home. However, there are techniques available for recalling past lives if you are interested. Hypnosis has been an effective means to recall past lives, usually induced by a trained therapist. Rebirthing breathwork is also known for inducing past life recall.

Please do keep in mind that past life recall may uncover past trauma which may be uncomfortable for you unless you are in the care of a trained therapist. Also, past life recall, if unaccompanied by remedial therapy afterwards, may cause traumatic memories to linger and disturb you. Once again past live recall should be done only by a trained therapist. It is not an adventure ride to explore the past and should be used only if you are facing issues (unexplained chronic pain which doesn't go away with medical intervention, unexplained dreams/visions, relationship issues with specific persons, fears/phobias).