Since my mind is spiraling like a balloon spewing air....
Could it be that Epicurus believed in beings which are immortal, not just imperturbable or incorruptible as we interpret them? We think in terms of a Big Bang and an expanding universe whereas he was doing some of the original reasoning regarding infinity. I seem to recall that he s the gods as being made of something special, in addition to living in the intermundia. Thinking as someone living 2000 years ago, why wouldn't this have existed infinitely into the past as well as the future?
OK, I need a nap now.