Reincarnation is about gaining experiences
The soul is not here to learn anything. Life is not a school where we gain more and more knowledge and then graduate.
When you go to school you go because you want to know something you don´t know. It´s expanding your knowingness. But if you already know what you want to know then you don´t need school.
The soul wants to experience its knowingness - not learn anything.
Learning would serve no purpose, because the soul already knows everything. The soul is an aspect of God (part of God) and God knows everything and so does the soul.
But when it decides to experience life on Earth the human body that it uses as an "energy-vehicle" will not remember past lives or being an aspect of God. So, the purpose for all us is to remember who we are. To remember that we are God in disguise.
You might say that God is "hiding" in each and everyone of us and our purpose is to find God within. The book The Paradox of Creation describes this in detail.
So, life is not a process of discovery through learning, but a process of creation.
The soul is here to create whatever it wants and through this process the soul gains different experiences.
It´s all a matter of living out (or demonstrate) what the soul knows in the physical. It makes the knowing "come alive".
So the soul creates itself anew, through the experience of creation.