I had never before heard of the Gravitational field having negative energy and I was so surprised to see how Prof. Guith through a simple thought experiment established it. And yes I do believe in the derivation as so far we have not encountered any exception to the conservation of energy and this also successfully shows that indeed energy would be conserved during inflation if we agree on the fact that gravitational filed have negative enegry.

incredible explanation.

Going to give it one more go.