Vencedor

Im agnostic and i was discussing hell with my gf (who is christian). Somehow we became incredibly confused by it, i'll try to explain our issue. According to the Bible the following is true.

we go to hell for eternity
we suffer in hell for eternity
this suffering is a punishment

now i brought in my understanding of what a punishment is

we are punished for doing something wrong
we are punished so that we will learn from our mistake
we learn from our mistake so we know not to make it again

now these two work together for a while. perhaps the people in hell will eventually learn they were wrong about God (i think they'd realise quite quickly) and then they will have learnt from their punishment. but normally after this the right course of action would be to stop punishing them, and they're in hell for eternity so it doesn't stop. They arn't even given a chance to make the same mistake so whats the point in even teaching them not to? My question is this, what is the real point of the eternal suffering in hell? If it is punishment, then please explain y my definition has got me so confused. If not, then there must be some other explanation for it.

(I've asked around 10 people, atheists, agnostics and christians this question and none of them have given me an answer)