Let me back this comment up with some reading material and useful resources:

http://decentsecurity.com/about/ (This entire website)

https://www.microsoft.com/emet (for Windows)

https://paragonie.com/blog/2015/06/guide-securing-your-busin... (basic web security advice for non-technical people)

You don't need AntiVirus.

I it is not that we don't need it but it is finally obvious that there is no reliable way to detect harmful software. All we are left with is putting each and every application in sandbox, unable to interact with any other software or user data. It is just very hard to make that user friendly and acceptable for average Joe.

This is basically my stance at this point.

Yeah, like condoms...

No, not like condoms. If STDs became blockable with common sense and condoms started shipping with perforations and prickles on the inside then yes, but that's not the case is it.

I think he was trying to draw an analogy between installing untrusted software, and getting intimate with untrusted people. Both are avoidable.

One obvious difference is that the consequences of mistakes can be higher for STDs then for infected computers, but that's the analogy.

Condoms also prevent pregnancy. This comparison is ridiculous.