I don't know for sure.
I do know that ever since I cut back on my pot smoking habbit I dream like crazy again.
So perhaps something in your diet might me the case.
Also, you might know that DMT is released by your pineal gland, concidered the 'seat of the soul' by many cultures, every night which is thee chem. that makes you dream etc.
when DMT is smoked in its 'pure' crystal form the more you smoke the less you remember of you trip (dream).
I always think that whenever you can't remember your dream you've just had a big dose released into your system.
Self protection I've heard someone calling it.
If we wouldn;t dream we would, according to mainstream science, go crazy and or be very tired.
im not Karl Hungus