Ah, yes, I've done that - like you're lying in bed, and you haven't QUITE woken up yet, and you don't really want to 'cause you're feeling so nice and sleepy, so to delay getting up you focus on the dream you've been having, but your mind is half-awake now, and only partly operating on REM logic - so instead of just lying back and letting it wash over you, you start filling in the blanks and tightening up the bits that don't make sense, until by the time you wake up properly, you're all excited about this wonderful dream you just had - only you only partly had it, 'cause it's mostly revisionism at this point. Is that what you mean?