Do you know that our bodies are made of the same atoms that form stars and planets? the entire universe is energy, and energy cannot be created or destroyed...it just changes forms. So think of yourself as made of pieces of Lego...when you die, the pieces come apart, either completely disperse and each unite with different atoms, or chunks of it still stick together and other new join it to form something else. If a large enough chunk of the original Lego build stays together, there is recollection of previous life.