I am good at drawing, but only for things that are in front of me. Issue, is I can recognize face in split second, but I cannot recollect face. And, as I cannot recollect I cannot describe, if I say let say friend John, what I get is just abstraction of John, void blob. Someone already mentioned - imagine there is hash function, so once someone uses his password (face) I exactly know who is the person, but if you say persons name, nothing comes back, even remembering what he said, how he behaved or else, will not give me picture of person so I can use it from memory do describe and give distinctive features except he has two ears, nose, two eyes, maybe glasses, is bald... issue is you could explain same way most of the people.
If you don't notice the relationships of parts, don't break things down – you can't do it.
Don't be afraid of your dreams. They are part of you. Part of your mind, consequently brain, which is a body part.
When dreaming you can do much more than visualize. Dreaming is a different skill.
You can learn dreaming too.