what if is impossible to simulate a brain without ending creating exactly another one, brain use tiny space and mass, and in that confined space is very efficie

what if is impossible to simulate a brain without ending creating exactly another one, brain use tiny space and mass, and in that confined space is very efficient doing a lot of calculation that we are not even aware of, using the least amount of energy and dissipating the least amount of heat possible. have you ever feel that your brain is suffering from overheating?