The material you learn must be formulated in as simple way as it is

• Simple is easy
  By definition, simple material is easy to remember. This comes from the fact that its simplicity makes is easy for the brain to process it always in the same way. Imagine a labyrinth. When making a repetition of a piece of material, your brain is running through a labyrinth (you can view a neural network as a tangle of paths). While running through the labyrinth, the brain leaves a track on the walls. If it can run in only one unique way, the path is continuous and easy to follow. If there are many combinations, each run may leave a different trace that will interfere with other traces making it difficult to find the exit. The same happens on the cellular level with different synaptic connections being activated at each repetition of complex material

• Repetitions of simple items are easier to schedule
  I assume you will make repetitions of the learned material using optimum inter-repetition intervals (as in SuperMemo). If you consider an item that is composed of two sub-items, you will need to make repetitions that are frequent enough to keep the more difficult item in memory. If you split the complex item into sub-items, each can be repeated at its own pace saving your time. Very often, inexperienced students create items that could easily be split into ten or more simpler sub-items! Although the number of items increases, the number of repetitions of each item will usually be small enough to greatly outweigh the cost of (1) forgetting the complex item again and again, (2) repeating it in excessively short intervals or (3) actually remembering it only in part!
  
  
  WRONG:(
  
  Q: What are the characteristics of the Dead Sea?

  A: Salt lake located on the border between Israel and Jordan. Its shoreline is the lowest point on the Earth's surface, averaging 396 m below sea level. It is 74 km long. It is seven times as salty (30% by volume) as the ocean. Its density keeps swimmers afloat. Only simple organisms can live in its saline waters
  
  GOOD:)
  
  Q: Where is the Dead Sea located?
  A: on the border between Israel and Jordan

  Q: What is the lowest point on the Earth's surface?
  A: The Dead Sea shoreline