I too have fairly vague notions regarding heaven and hell.
Though I was raised in the concept of "ever-lasting punishment with unrelenting agony of burning and unquenchable thirst" it amazes me that I believed it and feared it for as long as I did.

If there is a god, vengeful or otherwise, then, yes, I can believe that extinguishment is a possibility. I can even accept that any creator has the right to knock down the tower of blocks.

But hell as in the first depiction? Nah. For one reason: We know instinctively that to torture is wrong, is evil. And a creation cannot be better than its creator.

And heaven? There have been brief periods in my life that felt like heaven. A period of time and space where I was exactly where I wanted to be and doing what I wanted to be doing and with exactly the right people around me.

A literal heaven? I suspect that "heaven" is a transitional place, a graduation if you will, a completion of one level.

A little segue here: Has it ever occurred to you that Zeus and Athena and all the rest may be our gods in reality? Yoicks.