Does a person have to have learning difficulties in order to think that hell actually exists?

No, that's usually the result of an otherwise healthy mind being subjected to childhood indoctrination.

You should know! .

No, just faith in what God has clearly revealed.

It's usually because of the teaching being handed down. The article below might interest you since it discusses the origin of hell.

I don't think this has anything to do with learning difficulties.

The idea, and in many people the fear, of hell is often planted in people's minds at a very young age.

Children are hardwired to believe what they are told. This is a good thing because in many situations it is critical for survival that young children follow the orders of their parents. A child not listening when told not to step into the street without watching the traffic might not live very long. (And in ancient times, a child not listening to the warnings of their parents not to touch this particular snake or to stay away from that lion might also have gotten them killed. You get my point.)
So, it has become an evolutionary advantage for children to trust parents (or older people I guess).
In the case of religion, this seems to backfire. Or at least been taken advantage of. I think it is no coincidence that in many (most? all?) religions, children are taught their tenets at a very young age - an age at which they still believe pretty much everything unquestioningly.
That is also true for hell.

It is a nasty psychological fact that these concept that have been instilled profoundly at a young age and over a long period of time often evade rational thinking and linger on even if the people themselves should know better.
Not few ex-Christians that have become atheists still struggle with this irrational fear of hell, even though they know intellectually that they shouldn't be afraid. They still are.

Essentially, hell (as well as many other religious doctrines) are social memes that are passed on from generation to generation.
Luckily, the waning influence of religion, especially in the Western world (the US being a lamentable exception in many states), interrupts this passing on of religious memes more and more.
Over here in Europe, more and more parents raise their children without religious indoctrination.
Once grown up, most of these individuals will also not indoctrinate their kids with ideas of hellfire and brimstone, meaning that the next generation will grow without any irrational fear to overcome.

I have little sympathy for religion but I think that atheists should be aware of the devastating effects that religious indoctrination can have.
Unfortunately, many believers are rather victims of their upbringing who deserve more sympathy than they get from some of us.
(The irony isn't lost on my that I'm advocating for an approach -to detest religion but not the religious- which is quite similar to the famous "hate the sin, love the sinner" principle!   ;-)

Who does not have learning difficulties? Whether it's a new language, physics, or riding a bicycle; that's what learning is.

Anyone who believes that FANTASY=REALITY
has AT LEAST one screw loose, probably more.