As far as I know vivid dreaming is not equivalent to better recollection of dreams. A dream is vivid when and only when you are aware of the fact that you're dreaming while it happens. It isn't necessarily true just because you're able to recall.
That's not at all what I meant by "vivid." I meant clear and intense, not necessarily a lucid dream. I only mentioned that recollection may be equivalent, because it's possible that, while not using melatonin supplements, I was technically dreaming just as much, but my sleep/wake pattern was such that I never recalled the dreams in the morning.
