The missing bit should have been "when Norton Internet Security totally broke my internet and stopped me from accessing web pages and generally didn't work right". That (plus the fact that Norton AV is/was a huge resource hog) is the reason I blacklisted Norton.
I also stopped using PC firewall software after that and now rely on what Windows has and what my router is doing (it may not have a specific firewall but the NAT does help to prevent certain attacks from making it all the way to my Windows PC)