Common Sense
That only works if you decide to never go on the internet. There's stuff on perfectly legit websites that the website owners don't have control over that can give you viruses. I've not been on any sketchy sites and Avast picked something up just a while ago on the forums. Don't even know what it was, just something about an image. Might've been another site in the background but again, I wasn't on a sketchy site.I use avast and would like to switch though
https://en.wikipedia.org/wiki/Exploit_(computer_security)Also, to put into context why thinking this is a /really bad idea/, allow me to state a similar argument in similar terms:"I don't need vaccines! I have common sense, I won't get sick!"In conjunction with an antivirus it's decent, sure, but don't trust your sense to save you.
you have to run an executable or approve a java applet to get a virus. simply visiting a website won't give you a virus unless you're using an ancient version of internet explorer that's vulnerable to activex exploits.