Over the years, I've noticed that IT equipment has a habit of simply disappearing. When you absolutely know you had several power adaptors, spare memory chips and patch cables in the cupboard, and yet the most diligent search doesn't reveal anything more than a dusty old graphics card or 300MB HDD, then you become aware of the essential fragility of nature.
I'm not sure about the power strips or memory, but I do know why the network cables go. Anyone who has worked with a patch panel and network infrastructure very quickly becomes aware that network cables inevitably become tangled. You can leave things as neat and well-laid out as you like, but once you close the server room door and turn the lights off, those cables start to squirm and wriggle, and eventually end up in a state that makes a bird's nest look like a rigidly formatted mathematical progression. There's a Nobel prize waiting for the first person to invent tangle-proof patch cables.
Eventually, the cables reach a state of complete instability - the knots are so complex and topologically impossible that reality can no longer support their existence. And poof - no more network cable. Note that this only happens to cables that are not in use - there must be some extra dose of stability introduced by the passage of TCP/IP packets up and down the line, something that helps the cable keep a tenuous grip on existence. But for those wires left on the side, or simply attached to dead port switches there's no hope. Eventually they will pass over the edge of normality and there's a small collapse of matter in that region. It must be small, because no energy is released - possibly because it's all taken up in maintaining the complexity of the knots. And so, when you come to look for spare cables for that essential new link, and you remember buying a dozen or so 1 metre patches just a month ago, but none are there, then you have proof that matter can destroyed without trace.
Either that, or one of your co-workers has nabbed them for another site.
