The medallion was already activated. From the moment I picked it up, I was beginning to reveal my innermost desires to it. I didn't even notice, until I walked into a wall and realised that I had been thinking about how I had a crush on a girl three inches shorter than me, and was it maybe because I couldn't cope with the idea of a woman being taller than me.
So I sat. And I meditated. And I tried to communicate with it.
It spoke of another world. A world that it had nearly destroyed, by being owned by an evil man, who used and abused it's powers. So now it had been more careful. Every person who tried to take the amulet was gently whispered to. Mesmerised, into giving up their secrets to it. Talked into bearing their mind and soul with words of honey and a tongue like sugar. And it had been so stringent, that until now, no one had passed the test. I was the first. After millenia of waiting, it had found a pure heart.
And it wanted to help me.