A simple way to understand E=mc^2

We all would have heard about the Einstein's famous equation E=mc^2 , but do we really know how did this equation originate or derived

Consider you are sitting on a chair for a long time ,this means that you are not moving anywhere but in a rest state , now if we define ur momentum in space it will be zero as u r not moving , and also u r kinetic energy will be zero, but what about your energy due to mass , this will be equal to mc^2.

This energy E=mc^2 is due to your momentum in time dimension !

You are always travelling in time , Albert Einstein used 4 dimensions in relativity which included time as another dimension which gives us the energy due to our mass.