Q: how did you make those cool backgrounds with a million copies of an icon or piece of text scrolling past each other?
A: tile the thing, save as hi res image, by the way if you don't have any tiling software, you can just copy then copy them both and then copy all 4 then copy all 8 and 16, 32, 64, 128 etc. then get 2 images and set them to different composite/blend modes or transparency, then scroll them past each other with a linear keyframe. then for some extra fun, export that video then re-import it and double it and gently do a hair or 2 more things on it. then if you still have time to spare, do it again