Boiling an egg

As someone who does this often, I enjoyed this article. I usually boil 4 or 5 at a time and the problem for me is not the "done-ness" but why are they so hard to peel? The article claims the following:

As anyone who's had fresh-from the hen eggs will tell you, they do fry up beautifully, giving you tall, tall yolks, and tight whites, and trying to peel a very freshly laid boiled egg is difficult—the inner membrane of the shell has a tendency to stick to the white, giving the peeled egg a pockmarked appearance. But these differences disappear within a few days after the egg has been laid. Since eggs in the supermarket can spend up to 30 days before they even hit the shelf, followed by a further 30 days before they hit their expiration date, the point is pretty much moot.

Unfortunately, it is not moot because occasionally, 3 out of the 4 will be easy to peel but one will not. Why is this the case? This is even with an effort to buy a carton of eggs and keeping it in the refriegerator for 1 week.