Manipulating Memory

Many years ago, when I had more free time to peruse online magic forums (fora?) there was a topic of conversation that came up fairly often. It went along the lines of, "If you had twenty people stranded on a desert island, would you want one of them to be a magician?" Ergo, ipso facto, magicians are useless... and so on.

I'd be hardpressed to get a magician into the top twenty. I'll admit there are higher priorities like shelter and food and medical care. But there is one public service that I think magicians deliver almost better than any other profession. We demonstrate how our perceptions and memories are not as reliable as they feel. 

You, like me, probably feel most of the time that your eyes are more or less like a video recorder, but what's actually going on (and I'll be the first to admit we only have a superficial understanding of it) is pretty far removed from that.

Take this simple test to see how your memory is and whether it can be manipulated: