The other side is actually the Spirit Realm, where our spirits reside after we leave this human body. The realm is where we live as our true self between this life and many other lives.
Our Soul or the spirit is a pure form of energy. Energy vibrates at different frequencies at different levels of creation; however, as we don the human body, the vibration lowers down a bit as we then confine ourselves to mind-body dualism.
As the soul leaves the human form to achieve its true form – there is the initial feeling of shock. There is a total sense of release; however, it takes time for the soul to start vibrating on the light energy. Before the soul takes it true energy from it passes through a lot of phases and meet all its loved ones who are vibrating at a much higher level so as to receive the shock with ease.
When a soul crosses over it has a choice for the other side to look as it wants it to be, initially it all looks like Earth, but as the consciousness rises and the soul adapts to its truest form – the consciousness of the place changes accordingly.
Every spiritual being experiencing human form has a spirit guide. The Spirit guide helps a soul transcend from the earth plane to the spirit realm or the other side. The guide brings along the spirit energy of all the loved ones for a soul to cross over from earth plane to the other side or the spirit realm with utmost ease.
A soul that finally crosses over from the earth plane to the other side takes with it all the knowledge through books, experiences, all the emotions and feelings. The only reasons why some people seem more mature at 15 whilst a 45-year-old seem stagnated in the thought process. It all depends upon how many times a soul has incarnated and learn the lessons well.
The soul takes the form as it wishes to look like. It could be a 101-year-old wanting to look like its 25-year-old self. It all depends on the consciousness level of the soul journeying towards becoming a spirit.
A soul is a connectedness between the human form and its true spirit form. Spirit is essentially the true energy form a soul is. The soul is the form that remains with the human form in its humanness and with the spirit in its true energy form until the spirit decides to leave the worldly cycle finally.
As a soul reincarnates it takes the essence from the true spirit. As it incartes as different human forms, it keeps flexing itself accordingly until it has taken all that is needed for it to evolve.
The Higher Self is your spirit form that is always present in the three-dimensional reality to help you evolve through stages and phases that you have decided for yourself to learn through the course of your life you have chosen for yourself.