What does it mean to be a "soul?"
body minus soul equals no action
We’re not bodies that “have” souls. We’re souls who have bodies. Souls don’t require bodies to be able to live. Bodies without souls are called “dead.”
Souls are real people, with unique personalities—complete with senses, mind, and intelligence. Souls don’t die, don’t get “old,” never cease to exist, and always maintain their individuality.
Souls are spiritual. “Spiritual” means perpetually joyful and perfectly conscious. Why do we not like pain, death, sadness, and being confused about what to do next? They don't feel right because they are the exact opposites of our natural, spiritual life symptoms.
The natural activity of souls is serving the Supreme Soul—God—in a unique relationship. We may try to avoid this, but it’s the only activity that can totally satisfy us. Our spiritual nature demands we must love and serve something.
Because we have free will and some independence; we can either direct our love and service to God (a.k.a. Krishna), or imagine ourselves to be supreme—in a temporary, illusory (non-spiritual) world.
A life of illusion can never satisfy a spiritual being. Eventually, every soul in the temporary, material world becomes convinced that there must be something more. At that time, the soul may again be curious to learn about his spiritual nature, and eventually want to re-establish his eternal relationship with Krishna.