Wow! 10 years of only using computers operated and actively maintained by users who can stay up-to-date on security best practices. You made it from before XP until now without ever dealing with Windows malware! You're pretty damn lucky - I sometimes use computers that belong to laypeople :-(
It really doesn't take state of the art security, it just takes some healthy skepticism when browsing the web. If you know not to click on flashing red banners, you'll be okay. I went without antivirus for years, but now I just run MSSE in the background as it's so light. It's only alerted me to false positives so far, but they're few and far between.
I will say that if I'm suspicious of a file (say, a dll I had to go find from a shady site), I'll scan it over with a few tools before dropping it in a program folder.
... And not having Java loaded in your browser and/or using Internet Explorer. The number of CVEs related to Java file execution vulnerabilities astounds me on a monthly basis.
If you want to do one thing to ensure your machine stays secure, don't browse with Java enabled. I can't tell you how many countless sites our users find when a new Java vulnerability appears.
Malware writers seed countless sites with things like the Blackhole exploit kit on improperly protected blogs with decent search rank - landmines waiting for the next unsuspecting Windows user.
- signed "someone who has dealt with more infections than he cares for"
It is also possible that you are not aware of the malware in your machine. Many pieces of malware do not require any click whatsoever to install themselves--merely visit the wrong webpage. These types of malware also are typically smarter about hiding their tracks by not dogging the machine's performance, popping banner ads, etc.
To be fair, this was also the case with Flashback. No user action was required other than loading a web pages.
Nor is your claim that malware hasn't affected your life using Windows in the last 10 years. Even if it's actually true, it's at least a 4-sigma event.
I have a whole family of Windows users and none of them have gotten a virus in over the past decade. None of them except for me are very technically inclined either. However, they don't visit porn sites or pirate software either.
The last virus that I personally got was back during the Win95 days. It was the NY Boot Virus, which I got by accidentally leaving a floppy (which I got from someone at work) in the drive during boot.
