The later half of the rule also scales the estimate up by an order of magnitude, would imply tasks taking 30x longer. Guess that makes you quite optimal at those tasks.
I could be wrong because I haven't read unabridged versions of either. My sense is we tend to relate what was described abstractly with advancements we see around us.
For e.g. with flying vehicles in ancient epics I'm skeptical that they describe in any detail how flight was achieved besides magic or divine power.
I can see what you are saying, the downside is pretty much nil. And it seems like people do buy more guitars than just one. I'm currently just entering this phase where I just now stopped regretting the purchase because I couldn't play any music out of it initially. :)
Not sure if it fits with what the poster you replied to was saying but I find it a bit curious when I buy say a guitar on Amazon and my recommendations (emails or ads in other sites) over the next few days are still guitars. I do not remember seeing one of those promotions which follow a purchase being about accessories or add-ons.
I'd just like to interject for a moment. What you're referring to as Linux, is in fact, GNU/Linux, or as I've recently taken to calling it, GNU plus Linux. Linux is not an operating system unto itself, but rather another free component of a fully functioning GNU system made useful by the GNU corelibs, shell utilities and vital system components comprising a full OS as defined by POSIX. Many computer users run a modified version of the GNU system every day, without realizing it. Through a peculiar turn of events, the version of GNU which is widely used today is often called "Linux", and many of its users are not aware that it is basically the GNU system, developed by the GNU Project. There really is a Linux, and these people are using it, but it is just a part of the system they use. Linux is the kernel: the program in the system that allocates the machine's resources to the other programs that you run. The kernel is an essential part of an operating system, but useless by itself; it can only function in the context of a complete operating system. Linux is normally used in combination with the GNU operating system: the whole system is basically GNU with Linux added, or GNU/Linux. All the so-called "Linux" distributions are really distributions of GNU/Linux.