I find that if it's an elaborate dream that happens toward the end of sleep like this one, where I wake up fully at the end of it, I can recall it in minute detail if I spend a moment deliberately reviewing it before it slips away. Then images stick in memory, and often a lot of the narrative, if there is a narrative to it. Also, I fairly often have dreams where I am close enough to coming out of sleep that I get consciously aware that I am dreaming and can exert some control over it or end it if it's unpleasant. But ones that happen during the middle of the night where I might wake up a bit but then go dead asleep again right away don't stick in memory with any detail. It's such a strange thing how that works.