Please Read:
Gone and Forgotten

Excerpt:

“Oh, they see me. Their eyes, at least. They’ll walk around me never noticing I’m there. It’s kinda like what your brain does when you’re walking down stairs. You know the stairs are there, but you’re not necessarily thinking about them. If I make a point of it—one time, there was a fire, I grabbed someone and made them see, but even then, most people will forget.”

The strange speaker smiled at this last word, his eyes darting out the window.