$55 for lots of info. Don't need to use the frontal lobes for this decision.
Each covers some stuff. Some overlap occurs. Redundancy is the basis of learning.
My sadness has been the lack of audio only instruction. I spend too much time in cars. Would be good to have the sound tracks to listen to. I have recorded the audio to CD from previous vids. Most do not just move to the next lesson, so had to remember to also click the "next" button, and not stop to rewind or ponder.
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The lesson of the day:
"Completion" only happens in between humans during contests (games) of winner take all.
It does not apply to products, companies, objects, ideas, animals, trees, mountains,......
Completion requires intent. Only humans can have intent to compete.
Sadly this concept has been woefully misapplied for decades. With the resulting interference of intelligent thinking and actions.
It is a "Pavlovian-Salivation" word used to invoke the image of a contest where none exists; To elicit a very subconscious, visceral, response to side with the person who is uttering it. ("The American People" is another such phrase.)
Ask 10 people what the word/concept means and 10 variations will be the responses.
The appropriate word/concept for products is "comparison." And this comparing only has relevance to how each of the products will meet a user's particular requirements.
People in business organizations that spend most of their time worrying about what their "competitors" are doing so they can "win," do less innovation, and thereby create me-to products. Often of less quality and consequently more expensive for lifetime use.
The above comments are a summary of 40 adult years of study (thousands of articles, books, videos), and observation of self and others during everyday living.