From my vantage point of understanding, I have not seen that much accurate description of what an "old soul" really is and yes, there are "old souls" here on Earth but it is not what you may think.
Here are seven descriptors from Kryon, of magnetic service, as channeled by Lee Carroll, that I find to be an apt definition of an "old soul." I share them with you here:
1. "When it comes to the energies of beings like Kryon and the information given, old souls are a sponge for this information because this information is beginning to ring with the truth of the age.
2. Akashic awakening-remembering things as in a deja vu feeling. For example, seeing the digital readout of 11:11 which is a delivery system to old souls so that they know they are old souls.
3. Deeds you've done ring in your Akash and it's part of your cellular structure like being a mother, warrior, killing someone or dying on a battlefield in a previous life.
4. Wisdom beyond your years-your wisdom comes through experience. You've paid for it.
5. Because of previous battles with old energy ( burning at the stake, etc.), you carry an attitude of a complete lack of self-worth. Your experience through history has caused you to search your mind to see if you are worth being here now in this new energy.
6. Discovering purpose. As you begin to change yourself from the old ways, your power really starts to show. Simply "be here." Your works are not as important as your presence. By being here as an experienced soul, you put your experience of wisdom into the grids of this planet, the energy of the maturity of your lives. This planet is absorbing everything you've done and maturing because of it. Relax and be. Your wisdom gives you a common sense glimpse of the mind of the Creator.
7. The old soul in this energy has the ability to feel profoundly loved by God and others do not."
I hope this helps you with the vernacular of what is commonly called an "old soul." To really understand this is quite important.