While on the path of self-exploration, we constantly look for clues that our soul has hidden for us in this life. The tale of its journey can be put together by being respectful and having undeterred faith in its presence.
We don't know which number of birth is that we are living but the reason we are here is to fulfill an 'unfinished' task. Besides the task, we experience pleasure too in various forms.
It is uncertain to say what has and what has not been lived by us but few relationships that influence us deeply in the present lifetime are bound to be traces of past acquaintanceship. If a person behaves in an evil manner and brings about a setback to you, then you get too busy repenting or cursing the time that you spent with him. Yet, it is to be understood that the jolt had to be delivered to you as a pending lesson.
And, if you meet a stranger and the encounter transforms into a faithful, rewarding and long lasting relationship, then it can be understood that you may have shared a relation of welfare and benevolence with each other in some previous birth. The result of it is evident as you stay in touch for as long as either of you have to go away for any reason. Close friends, siblings, godparents, parents are the manifestation of such souls
For the soul to grow and continue filling its bowl of wisdom through experiences, it makes us travel through various lifetimes for the related tasks are long and tedious. For example, if you are supposed to meet 50 people to learn the lesson of being a teacher, through means of desire and communication, you will come into contact with those many humans. If you are unable to fulfill the task in this life, you will have to return and finish the pending work.
Interestingly, the planned set of life experiences only enriches and educates your spirit to the point where you can stand witness to cosmic consciousness and be free from the karmic cycle of life and birth.