This reminds me of a scene in Neil Gaiman's book, Neverwhere, where the main character finds himself pretty much edited out of everyday life. He's not invisible, but he's kind of like white noise. People only notice him when he makes it impossible for them to do otherwise, like grabbing their hand or getting in their way and addressing them. However, as soon as he's out of direct sight, they can't seem to recall who they'd been talking to. Seconds later, it's like the conversation never happened.
Meanwhile, his workplace has given his job to someone else, and his landlord is showing off his apartment to possible renters while he's still in it.
I think the author was somewhat inspired by how the general populace treats the homeless, hence their prominence in the story. They're there, but we tend to ignore them as we walk by and forget them quickly.
