I remember when I realized I'd become immune to banner ads.

I had to sign up for a college related thing on a website once and I just could not see that sign up button. They made it a flashing advertisement sized block right above another article, with big letters "SIGN UP HERE". A friend sent me the link and I literally spent 5 minutes trying to find it in navigation bars and other links in the article. My friend had to send me a screenshot of his screen with a big red arrow pointing to the sign up block before I noticed it. I now use Adblock but for the times that it doesn't work, my mental Adblock seems to always help me out as well ( Especially for those sneaky ads mixed in between real articles ).