We all leave our body, our consciousness/soul self does, but most of us are unaware when it happens. We all leave our body at night. We have other work to do elsewhere, things to learn out of body, people to help, and so on.
Those traveling dreams you have while sleeping, may be memories of your travels while out of body, and at other times, when you are day dreaming or doing meditative work like knitting or gardening. You may not even be aware of the fact that you left your body. The experience is so seamless going from one location to another, one reality to another is mostly unconscious unless you know what it feels like and you are paying attention.
That's what Robert Monroe was able to do at will, leave his body and travel places. Eventually, he was able to connect with aspects of his higher self. He learned a lot from his higher self and was trained to overcome some of his weakest personality traits.
It all started in the 1950s when Monroe accidentally found himself out of the body, hanging around at the ceiling of his bedroom looking down on his body. Needless to say, it terrified him. At first he thought he was going crazy and saw psychiatrists to help him figure out what was going on. The incident was so shocking that it sent him on a big exploration to discover what was happening, which also included leaving his body again and again. Mr. Monroes was fearless and persistent. Eventually, he got very good at leaving his body. He wrote about those early experiences in his book, Journeys Out of the Body.
Over time he became better and better in his ability to leave his body and finally he met, what he called his INSPEC friend -- an aspect of his higher self. He documents those experiences in his second book, Far Journeys.
Then he created the Monroe Institute, in Faber, VA, to teach others how to leave their body at will. And he wrote his last and final book, Ultimate Journey, where he documents his many out-of-body journeys and encounters with his INSPEC and other non-physical beings.
You can go to the Monroe Institute today and learn how to leave your body, if that's something that calls to you to do.
The Monroe Institute also offer other teachings about the nature of reality and human abilities beyond the physical.