I'm pretty skeptical too. I don't think Clay gives nearly enough credit to people's ability to learn new things and forget the past.
I asked the two nearest people (one young, one old) the VCR/PC and radio/phone questions. The old one answered telephone without hesitation, and had to think about VCR. The young one did just the opposite. And, Mike Ramsay was in his 40s when he started Tivo.