From your comments, it seems like (1) refers to a single past event, whereas (2) refers to a habitual situation.
This isn't the point I was making, Hiden, and what I was saying has nothing to do with then and now. I'm confident that Loob was thinking of a different case.
I was concentrating on the difference between the past
closed conditional (Type III) - past perfect in the if-clause, past conditional in the main clause (
(1) If I had known it would turn out like this, I would have queued over there.) and the past
open conditional - simple past in the if-clause, past conditional in the main clause (
(2) If I knew it would turn out like this, I would have queued over there.)
This difference has nothing to do with then and now; in both cases we are considering what happened then - these are past conditionals.
It would help to have a more eventive verb than to know in the if-clause, and a simpler sentence.
Consider these two sentences, which use the same tenses, Hiden, as your (1) and (2). You were being chased by a large hairy man with an axe.
1a. If I had seen him, I would have hidden behind the lorry.
The condition is closed - YOU DID NOT SEE HIM. It's unlikely, therefore, that you hid behind the lorry.
2a. If I saw him, I would have hidden behind the lorry.
The condition is open. YOU DO NOT KNOW WHETHER OR NOT YOU SAW HIM. Maybe his fearful appearance has caused you to lose your memory of the event. However, there may be a street-camera film which shows that you
did not hide behind the lorry. This information, together with sentence 2a, tells us that you
did not see him. Had the film shown that you
did hide behind the lorry, then we could have concluded that you probably
did see him. Notice that the open nature of the conditional means that the street camera evidence can indicate whether or not the condition was met; whether or not you hid behind the lorry helps us to know whether or not you saw him.
Bear in mind that Loob and I are both British, and British and American English are different in their deployment of past tenses. I wouldn't expect an American to agree with much of this post.