If you do not understand why, then there is no point in discussing it.
Many people like to talk about the differences, mainly because they LIKE BOTH and are interested to see how they will keep them meshed, especially when you have some pretty major plot elements being dropped or altered.
I thought they kept fairly close to "script" in the first, although arguably condensed and definitely altered in some ways (age being a primary, but not crippling, factor).
The thing that works here is simple, for some reason people like to see books brought to "life". But if you are REALLY good at it, you may throw in a few differences that makes even the precognitient wonder "what will happen next?".