One of the most interesting things about collage is that it enters you into an active collaboration with something that is neither animate nor sentient. When I start a piece I can always see exactly what I want in my mind. And I get that about 30% of the time. I push the material in one direction, but it pushes back. Sometimes it's like a friend, making constructive suggestions or bending me to nuance things I've overstated (my overstated whimsy is a small environmental disaster). Sometimes it's just a force, inserting themes or ideas that change the landscape of a story, and I, at least, have to re-navigate it.