WHY are dreams so hard to remember?
The conditions of the brain during sleep do not allow the dream to be transferred to long-term memory upon awakening.
In addition, a lack of the hormone noradrenaline, which is responsible for long-term memory, also plays a role.
Another reason could be that neurons from the hippocampus do not work properly during the REM sleep phase, which prevents them from transferring information to other neurons, delivering sleep never stored in memory.
