Why?

One day, I was standing alone, all by myself, in a dark, cold room. With nothing to do on my hands, I was empty, for once, in mind, heart and soul. Out of boredom, I did what most of us would have done; I started going through that infinite wealth we all possess, namely, the bank of memories. Leafed quickly through some sour ones, chuckled at some naughty ones, before I came to a bunch of some fond memories. And then I was looking at a particularly warm one; I touched it, and the warmth coursed up through my fingers and enveloped my entire being. Within moments, I was actually able to see it, the image filling the room, bathing it in warm light. I reached out to touch it, to feel that warmth rush through my soul once more; but as soon as my fingers brushed against it, it shimmered, like a mirage, and disappeared, leaving me shivering in the cold, once again enveloped in darkness.