Suppose your job consists of carrying a briefcase of important documents from point A to point B, which is 3/4 of a mile line-of-sight across a swamp. For years, you have started the day, and set out on a road that circumnavigates the swamp. It is a good road, but it is 5 miles along the road to point B. Now, one day, someone comes along and says "here is a new pair of extra good waders. It will cost $50,000, but you can now take the briefcase, and walk directly to point B, saving oodles of time." Ok, so maybe it will be worth it. You buy the waders and set off. What they did not tell, you, however, is that cables have been strung just under the surface of the swamp at random spots; so you start off, hit one of the cables and WHAM! you're flat on your face in the mud. You pick yourself up, wipe off, and start again. WHAM! You hit another cable. This goes on several times, and you finally make it to point B about 15 minutes earlier than if you had taken the road, and you are covered in mud. Oh, well, you figure; you'll eventually learn where the cables are hidden.
What they also didn't tell you, however, is that the same people who sold you the boots go out every evening and relocate the cables. These are called "upgrades".
Last edited by dgrauman; 11/09/2011 8:37 PM.