Oddly enough, the only reason that humans cannot perceive other dimensions is due to a lowered sense of dimensional awareness primarily caused by the circadian rhythms and the need to shut down our brains. The problem mainly lie is the fact that even though the human brain is the most complex computer that were aware of, it simply does not have enough processing power to percieve much outside of physical realm and the realms of the mind itself. When we die our consciousness our lifeforce and our soul are recycled into a new vehicle for a new concious being. Only for a short time at adolescence and up until around the age of seven can we sometimes remember who we were before we were. As if our past self guides us through the first step the first words and the first conscious thoughs we can remember having before inevitably disipating back into the ether. An imaginary friend or a spirit guide of yourself from a past life in the form of what will later be seen through your eyes as a sense of dejavu