10 Things a new Linux user needs to unlearn

OK, you have Linux on your computer. Maybe you had some trouble getting it installed and everything working (probably wifi if I had to guess, or a winmodem), but you are past all that, everything is working, and you are ready to start using the computer. Old habits die hard, so hopefully this list helps you get over them.

Of course, rules would not be rules if there were no exceptions to all of the following, but in general all these are the way it is.

1) Reboots are not SOP (Standard Operating Procedure). If an application dies, or locks up (which is rare, but can happen, usually with bleeding edge versions of apps), your OS is usually fine. If the app window stays open, iconify it or run xkill and click on it, no worries. The same is true for updates, software installs, etc. Except for kernel upgrades (infrequent), the message "You must reboot for changes to take affect" or what ever you are used to seeing is a thing of the past.
2) "It is recommended that you close all apps before proceeding" is a message you will fail to see. There is no reason to stop listening to online music, surfing the web, downloading updates or new programs and/or flipping back to your word processor, all while burning a music CD. The mouse tie ups common in other "multitasking" operating systems doesn't happen. You know the one where the icon becomes an hourglass and you are free to multi-task once the computer decides to give you cursor control back.
3) You don't need to renew your spyware/spamware and virus checker subscriptions. Sorry, you will have to find something else do with your money. Of course, nothing Linux can do about phishing links, so always beware there, but know that if you install it from your CD or open source vendor, you are spyware and virus free.
4) Linux comes with many, many, many, many applications to do pretty much anything you want to do with a computer. You won't find many Linux applications at the store because 1) they are included on your CDs/DVDs and 2) A free copy is just a download away. Always search your CD first. (with the software install method for the program you want) It is likely there, a few clicks and NO REBOOT away from running on your computer)
5) Stop looking for EULA boxes. You may have to occasionally agree to the GPL, however, email keys, digging out the CDs to find that security code to install xyz, email reminders about upgrades, all that joy doesn't exist, it is all yours to use in any way you desire.
6) Autoconfiguration. After you buy that USB drive, or that printer (you did verify that it is Linux compatible), plug it in then start using it. Your days of loading driver CD:reboot, load application CD:reboot, load OS CD x:reboot, register-click through 6 EULA boxes then finally get around to configuring it are over. You plug the USB drive in, 10 seconds later, it is fully installed and configured, and up opens your filemanager, or a printer dialogue box opens (select paper size, resolution, etc). The same thing you saw during your install, the usual lack of driver configuration is SOP in Linux.
7) You don't need to try to find the Linux equivalent of "PC Doctor" or whatever you are used to. Linux does not slow down over time, installing 40,000 apps (if you have the disk space) does not corrupt anything and feel free to uninstall any app through your distro's GUI interface, you WON'T clutter anything up.
8) Defrag. There is no Linux defrag tool, so don't look for it. In Linux, disks don't fragment in any substantial way. If you keep you HD at 98% all the time, then some fragmentation (obviously, about 2%) can occur since contiguous space is not available.
9) Under the "Start" menu, or Linux equivalent, you will find applications usually (sometimes your vendor makes strange placement choices) grouped in logical terms such as Internet (for of course, internet applications) or Office (for office applications) or Games. This is counter to the usual very logical way of Start-->Roxio-->Easy CD Creator 5-->Easy CD Creator--> Creator (You mean you forgot that Roxio makes the CD creation software for your lightscribe drive?
10) You computer is yours. No one is phoning home to check up on you. None of your music collection is about to be obsolete. None of your players require any internet connection to a "validation server" and none of your computer habits are being sent to any corporate entity that "believes strongly in your privacy" while it collects stats, no program is going to ask for revalidation if you decide to upgrade your motherboard, or video card, or add 3 USB hard drives. Your computer is yours, and you are free.

Part 2, Things a new Linux user should learn or would want to know.

Happy Trails

TripleII

P.S. Not a rule, but a perk, Clippy doesn't exist and there is no open source equivalent.

Corrected: See the comments, Clippy hase been emulated, pretty funny too!