Indeed, it can be surprising how many people fall for these things.
I was dismayed a few weeks ago to hear my elderly Dad had fallen for one of the telephone scams, whereby a caller pretends to be calling from Microsoft about a 'problem with your computer', then guides the person through the process of actually installing some malware, before demanding a ransom to remove it again. Fortunately, although my father was taken in and tried to obey the instructions he was given, I know from experience how hard it is to guide him to do anything on a computer. I think the scammer gave up in disgust as well, and more than likely went home with a severe headache.
Sorry for verging off topic, just trying to agree that perfectly intelligent people (which certainly includes my father, even though he has limited computing skills) can still be taken in.