nonono
If you read again you'll see that it's not about requiring comprehensive knowledge, but just common sense and ability of understanding.
For example, my lingual abilities are pretty bad - does it make me dumbass? No, cause I try to do my best and don't require everyone to speak in my mother tongue.
Problem is that people stop trying to understand, need instructions for the most basic things and often it's still not enough. That's great that there are people that know much more than me, in terms of computers or other, like medicine you mentioned. I'm happy with it. But it's also knowledge.
Thing that puzzles me is intelligence as ability to understand and associate facts or create something new. Today, most people don't need to be intelligent. It's a matter of person, if he / she wants to increase potential of mind or simply be dumb. If everything that's needed is ease of use, it's pretty bad. Of course ease of use is important, but it should only be one of requirements, not the only one requirement.
Basic understanding - we may think that people don't need to understand computers - ok. But then - how to describe the fact, that you will put pills in your mouth, not ear or back, not being a doctor. Why do you know that crops need to grow, to be cut, transported and processed in order to bake some things. You know that bread doesn't grow in shops. You don't need to be a specialist for such things. You also don't need to be a professional to know that TV should be plugged to electricity line and aerial / cable. You also don't need to "know stuff" in order to guess, that if TV supports some new format, it needs to be fed with it in order to make you see it. But important is that you are intelligent enough to guess / understand it. Some are not.
