[TheAmazingIdiot]

The energy curve sounds like a parabola (f(x)=x^2) curve of "energy", where nothing can actually sit at 0,0 or go through it.

The energy translation used to flip a slight positive temp to a negative temp sounds like a reflection to the negative side of the curve.

[yaks_hairbrush]

Another way to look at it is that the important quantity is not temperature, but its reciprocal. Absolute zero becomes infinity under this transformation, hence unattainable. Heat energy will flow from lower 1/T to higher 1/T, and more heat energy added to a system lowers the 1/T quantity of that system.