You might want to read these articles, and with a google search you will find others:

Linux vs. Windows Viruses, by Scott Grannemann
Myth Busting: Is Linux Immune to Viruses?, by Jack Wallen

I also warmly suggest that you read the article linked above by jdkaye. As a general rule, Linux assumes that you are willing to document yourself: the more you do, the more freedom and benefits you will have. Of course Linux Is Not Windows, even if there are a few so-called "friendly" distributions nowadays, which attempt to turn Linux into some kind of Windows-like operating system. Don't assume, as many people unfortunately do, that Linux should behave like such distributions: unless you are willing to read some documentation, manual pages and other related stuff, in order to learn how your system works, you will be in stuck in "spoon-feeding" mode, and feel uncomfortable with your new system.

1 members found this post helpful.

What a great way of putting it, can I quote you on my blog site?

Wow, thanks. Of course you can.

This is my favourite description of the differences between Linux and Windows for puzzled newcomers, there may be better ones out there but I haven't found them yet.

Read, Ponder and Inwardly Digest...

Linux is NOT Windows

Play Bonny!

Several other posts have comments that I would have made, so I want to expand on these questions above.
Flash is a proprietary program, that its creator decided to stop updating it for Linux. (why it says a Linux system is behind, when a Windows system might play some video online)
That causes things like Linux to get moved to the next "standard" earlier. (HTML 5)
This is a problem with any non open source program, where one company controls it (they choose to update or not).
Also, Linux is Virus RESISTANT, that does not make it immune. Kind of like something fireproof, verses fire resistant, or bullet proof verses bullet resistant.

Linux is going to be alien to you, because of a couple of reasons. The language one is always an issue when trying to come from Windows, IMHE. (think British English verses American English) Torch/fag/bonnet means one thing there, and something else here.
Because of that, in the old days, a friend who worked for AT&T, used the Alias command on his system, so he could type the dos command and do what he needed it to. (alias may be something to look at later)
Second, the old quote about making an omlette without breaking a few eggs. Was your first uses of Windows without issues? There are distro's that make things easier and video's on Youtube can help you learn things (as well as sites such as this one), but fear is going to be something you need to overcome. Expect to break things in the learning process.
I agree on something as inexpensive as a PI, or a second hand computer is a great learning tool. This allows you to have something that works that you can go online, when you have a problem to try to find/learn a solution.

@malkorion it sounds as if you're best off with a full desktop distribution and also should limit your scope to situations where a graphical package management application does the installations for you. You're mentioning that it's difficult to install and configure stuff. True, it can be, and it can also be frustrating if it's something pretty complicated. I will grant that Linux doesn't always have the best installation ease. This is why I recommend that you have something like a full desktop distribution where there is a utility for finding and installing applications you desire. This likely will limit the totality of things you can install on your system, but also stands to make your installations succeed versus frustrate you more.

Unfortunately to address the thread title and describe how to grasp the concept of Linux, the realities for now are that Linux is not totally automated WRT adding/removing software as well as a lot of other things, so therefore understanding it better would then merit coming up to speed on things like the command line and ways to determine if things are working correctly. At the very least, Linux is far better these days than it was in earlier days.

What distribution are you using? Use Mint, add a Google Chrome PPA, and your needs should be nicely met.

At first congratulations for OP. Most people I know broke their Windowses after a year or two years at most. When you are left with broken Windows OEM version, then the choice for most people is rather obvious. I remember my own WIndows 98 was broken after one month. But to tell the truth who is using the same computer longer than two years? There are applications which require Windows and have no Linux counterparts. But all other tasks done under Windows can be done under Linux. And if numbers of sold copies of Windows drastically drops, then it could cause economicall disaster in USA and in the World. Probably this is all the truth.

I've installed Chrome, and Chromium as well, and I'm actually satisfied with both, both Chrome plays everything so far. So that's done.

I will read all the stuff you've linked in this post, and my other post.

I like Linux, as it's not a power hog, and my girlfriend was actually surprised about boot up / shut down speeds. Though I can't recommend it to any of my friends. Unless they want to try it for themselves. But my gf's laptop would be better of running a Linux distro, as it's an older machine.