[freedom9]

You posted . . .
"Think carefully, because space-time curves due to the presence of mass/gravity... "

Then you posted . . .
"Gravity is due to space-time curvature."

(Seems to me you can't have 'em both)

Is it possible that energy is just simply attracted to energy?

[Charles H. (The_r0nin)]

Actually, mass causes the curvature, but gravity is the effect we see from the curvature (the gravity part after the slash in the first statement was the remainder of something I typed and then incompletely deleted).

As for "energy attracting energy," this is demonstrably not the case. Massless particles (photons, probably neutrinos, etc.) do have energy, but not mass. This is why cosmologists have been fighting over whether neutrinos do have mass, because it would explain part of the composition and gravitational effects we see in galaxies, despite the fact that we don't see the mass to cause them. So energy does attract other energy, but only when both energies are in the state that we call "matter" and have mass (remember that Einstein's famous equation establishes the convertability of matter and energy: E=mc²)...