Updated: May 27, 2008
I was a Windows user for several years when I decided to switch to Linux, late 2005 or early 2006, can't recall exactly. I remember that on Windows I was always looking for legal software, and freeware alternatives to all those paid applications. I was not aware of the terms 'open-source' or 'free software' back then, but still looking and searching I bumped into Linux and decided to give it a try. First it was Red Hat 9 for a couple of days, then I discovered Ubuntu. After about one month of dual booting with Windows I finally made up my mind and wiped it out, leaving all the hard disk to a freshly new Ubuntu 5.10. I knew when I started that the transition will be tough for me; things are done differently on Linux then on Windows. And it's pretty hard to get unused with a way of doing things which was in my blood for about 6 years. But what made me stick to Linux and never return, what kept me getting used to all this new stuff and a new, different way of doing things, was the pure fact that I knew Linux will be different and I must have to make an effort, I understood that I'll have to learn most of the things again. And I was prepared to do it. From the start, Linux offered me flexibility and free choice, with no fear on using the software or sharing it using BitTorrent or Direct Connect. And it gave good results: I'm a happily and passionate Linux user for three years now, and I'd never go back. I can't imagine going back and leave all this behind.
I think the main reason most of the people try Linux and go back to Windows is that they aren't determined to make the switch. If something is done differently on Linux, they quickly jump to a conclusion that goes like 'This is not right, on Windows this is done the other way around. It's no good.' Or the eternal, endless and already legendary proposition which us, Linux users, are tired and bored of hearing, 'On Windows everything is easier'. Well, I usually smile now whenever I hear it or read it. Once you get used to something, it's hard to do it the other way around, especially if you're not determined to do it or at least give it a good try, not just 'this doesn't work, I go back'. This 'easier' stuff is so relative, and why do I think that? Well, to give you an example: I got used to rip flac files using the flac and oggenc command line tools, I also have several small Bash scripts to ease my work. For me, this method is the 'easiest' and fastest, maybe another person feels more comfortable using KAudioCreator, for example. Or some other GUI application.
I agree, when I first started there were many things which I didn't understand and which I felt that were not right. Believe it or not, it didn't seem logical to me that Linux allows two files with the names 'Music' and 'music' in the same directory. Was that because it really wasn't logical? Simple answer: no. It was because I was used that way in Windows. Or, to take another simple example, the lack of 'Apply' buttons in GNOME applications. I just felt like the options were not applied if I didn't have that button there. But I knew it's different, and I embraced it. I kept reading forums and articles, and many other tutorials; I started to love what I was learning, and the whole Linux as an OS together with the open-source development method.
Most of Windows users expect the change to be fast and smooth: they expect to find in Linux all they have in Windows; it's a known issue. When they find out it's not like that, all is over. Linux is no good and they go back to Windows. If games are not ported on Linux, it's no good; if drivers are not available for Linux, it's no good; if I can't receive files using my favourite IM protocol - then Linux is no good. Unfortunately this is pretty much what happens inside the mind of a long time Windows user trying Linux for the first time.
Windows and mainly closed-source applications drive to a strange mentality. There was a thread on the Battle for Wesnoth forums (a TBS game for Linux, Windows and Mac, licensed under the GPL) about some guy selling the game on CDs on eBay. Believe it or not, the guy was highly criticised by several players posting on that thread. The reason was 'he should ask for permission' or 'isn't this illegal?' Now, I really don't have to mention whether they were the Linux users or the Windows ones. Don't get me wrong: I'm not criticising the people, but the mentality behind.
I remember I had this friend, pretty techy guy, who decided to switch to Linux. He was pretty determined, so I installed Kubuntu for him and tried to help him and explain the best way I could how to solve his problems on Linux. He was open-minded - I remember he tried to make Alpha Centauri work a whole night, with no intention on giving up. Whenever I could, I tried to help him; and he took my advices and stick to Linux for a while. Well, eventually, he finally gave up. Maybe I didn't try enough, or maybe he depended too much on Windows. I'm not sure. The thing is, if I would have tried harder, he would have probably ended using Linux today.
I think there's no chance for one to switch, unless he truly wants it. He may be lucky like me, clever enough to know what awaits and how to try and deal with it, or may need help from someone who has already been there and knows how to prepare a convert for this wonderful Linux world.