Unprepared for class again, Mr. Potter?

Okay, so it's a mild pet peeve of mine when people show up to game and they didn't bring most or all of what they need to play.  Yes, I've forgotten thing myself but stop changing the subject.  Some players are chronically unprepared.  Character sheet left at home?  Forgot the dice bag?  Hey, can I borrow something to write with--and something to write on?  You get the picture.  On the other hand there are the true gaming professionals.  Always equipped, always there, always on time, often with cool gaming support technology.   Luckily this isn't a very big problem with my group.  I just felt like venting a bit.