I can still picture things in my head, but with huge gaps and difficulty; when I was a kid, I used to replay a 17km road to my grandparents with exquisite details in my head: the bus, the driver, walking down the isle, seating myself, the initial jolt, watching the road turn, every unique house, porch,bench, tree, telephone wires and so on and all without a conscious efort "what happens next" .
If I try real hard and ask myself questions like "ok, so now picture grandpa's mustache, now his hair, now his neck" then maybe I get a glimpse of his whole face.
My sister and I used to play a game as teenagers: one of us would closd his eyes, the other would narate a scene, it was pretty great.
In the 7th grade I was a 6/10 student at math, then trigonometry came and I was a 10/10 at trigonometry and 6/10 at algebra, because trigonometry made absolute sense because I could draw everything in my head; I needed tutoring with algebra, but never with trigonometry.
I also almost never remember any dreams; my rem and deep sleep are toast anyway, according to fitbit.
As opposed to my childhood when I woke up exactly once per night to drink water from the cup my grandma left beside the bed -- the rest of the night I had great adventures, I'd be chased my demons, fly across the clouds, escape some trap my grandfather told stories about.
Nowadays I get about 1 hour of tossing and turning througout the night, and depending on my anxiety I sometimes get completely wake for 1-2 hours at about 4AM; only about 1h of rem and 1h of deep sleep, the rest is just light sleep according to fitbit.