This one might be a little insider baseball.

Y'know what really grinds my gears?  Terminal commands on  Linux.  Anyone who uses any Linux based OS knows that if you want to do anything more than just the basic layperson stuff that comes bundled with the OS (like word processing, web browsing, listening to music, etc), then at some point you're going to come face to face with the terminal (aka the console or command line) for some advanced operation.  I don't mind this, but what annoys the piss outta me is simply the fact that there's no standard manual or reference for the damn console commands!  How is anyone supposed to know what they are??!  MAGIC??!!  The only way that I have ever figured out how to learn a command is to google it and find some friendly, helpful user on Ask Ubuntu, or OMG! Ubuntu, or It's FOSS that shares their divine computing wisdom.  And there's no shortage of those people--any command you want to know, there's somebody who's posted it.  But why should that be the only way?  And how did those people learn 'em, huh??!  MAGIC??!!  Why don't the distros have a website with a comprehensive manual of console commands so that one can actually learn rather than just randomly googling until you find someone else who's posted the answer??  Drives me nuts.