Next world? Where will THAT be? Mormons speak of a planet called Kolob... /shrug Could that be it? Sounds rather Orweliian to me. Too much gray area to contemplate.
How will we know what we did in our past life? If it's all NEW, it must mean we died THERE to be HERE. Cetainly we won't have a reason to retain what we learned THERE so it could be applied HERE, yes? There's too much supposition in your thoughts.
Then you mention incarnation! Whoa! What's it going to be.... Next World, or same world except reincarnated but with the memories of the past life? That would rather muddy up the new incarnation, if you had to relearn everything while remembering the old YOU? LOL
Yikes! Let me out of here!