I'm a pro user (or at least that's how I consider myself, unless I suffer from the Imposter Syndrome).
I don't click links just because. I just don't. Not once in a million, not by mistake. I just don't.
I don't install software that comes from an "Unknown Publisher", even if I have to have it. I just don't.
I use CCleaner for a long time, as it's considered trusted, reliable and crap-free.
I did install the dodgy CCleaner 5.33. It was digitally signed by Piriform: https://i.imgur.com/GlDiEJM.png
And yet, it contains malware that was injected to the build process, thus got it to be as part of the "normal" program files and signed.
The trust model has broken.
What could I have done differently?