Daydreaming

Over the last couple of years, I have become prone to daydream.  At least I think they are daydreams.  I suppose I must fall asleep for a small number of seconds, in which these dreams occur.  They are not like 'ordinary' dreams, insofar as I am aware of their brevity and suddenness, but also, and more curiously, they interfere with my fading memory.  In other words, they don't have the implausibility of 'ordinary' dreams.  I 'wake' from them wondering whether I have been remembering something in reverie or whether I have merely been asleep.  All very odd.  Thoughts on this from my myriad readers most welcome.