I've read that artists, designers & craftspeople keep journals: filled with inspiration from travel, gallery visits, etc. They're filled with sketches, swatches, tear sheets, photos... all for future use. I keep one too, but it's in my head.
I have a "thing" [call it a phenomenon, a condition, a talent or a quirk] called Eidetic Imagery. Here's the Wiki definition. Anyway, almost anything I see, that really makes an impression or resonates on some level, goes into that mental filing cabinet for future use. I can actually physically recall images from the past - a face, a place, a set of tiles, a painting... a movie... and see it in the air, as if there is a projector in my head, using my eyes as the lens... an invisible screen at my disposal is within 15 inches of my face.
I often stammer for words - just can't remember the right one...and please don't ask me what year something happened [other than birth of child or year of wedding] or what I had for lunch two days ago...or what I walked in here for... but images, they're always there for reference.
Another thing - my 8th grade science teacher told our class not to study - that we should "rely on our ability to recall," which I might have taken a little too much to heart - not knowing yet about Eidetic Imagery. I remember things that happened in that classroom [Hi, Gaelyn], but I would say, that's not the best advice for teenagers more interested in drawing daisies on their hand during science class.
So, my journal - my head - is filled with images of the classic works of art - from art museums and books, not to mention photos from magazines, charts, maps, comic strips, ruins in Ephesus, people I know, couture collections, my room in Reading, PA, my dorm room in Oneonta, my room on a Kibbutz in Israel, a pair of shoes I bought in Italy when I was 18, a pair of shoes I wore in that 8th grade classroom, the shoes I wore to my high school reunion, jewelry, paperweights, and the image of my husband the first time I saw him in a swimsuit [think Vitruvian Man]... you get the picture [!]... all jumbled and/or filed. And, all available for use.
I usually don't watch a movie more than once, I can see it any time I want. I actually watched "District 9" again the other day, it's so filled with images...but I really liked the story. I could watch "Monty Python and the Holy Grail" another 35 times... but that's just for laughs. I try not to watch scary movies, because the image stays with me forever.
Disclaimer: I do have a few photos taped up in the studio, but I rarely refer to them. I also have a drawer full of photos that might be a jumping off point someday. I do have a shelf full of books - art books, Dover books, reference books...about costume, medieval design, beaded flowers... all kinds of stuff. And, a lot of music to listen to when I'm working.
When I fill a canvas with thousands of images, photos, words... it all makes sense to me, I could point at my head and tell you "You should see what it looks like in here."