1.0.: My answer to Feynman's question
Dr. R. P. Feynman (one of the founders of quantum electrodynamics) said the following wise words: \( ( \sharp_1 ) \) and \( ( \sharp_2 ) \).
$(\sharp_1)$:  There was a time when the newspapers said that only twelve men understood the theory of relativity. I do not believe there ever was such a time. There might have been a time when only one man did, because he was the only guy who caught on, before he wrote his paper. But after people read the paper a lot of people understood the theory of relativity in some way or other, certainly more than twelve. On the other hand, I think I can safely say that nobody understands quantum mechanics. 
$(\sharp_2)$:  We have always had a great deal of difficulty understanding the world view that quantum mechanics represents.$\cdots \cdots$ I cannot define the real problem, therefore I suspect there's no real problem, but I'm not sure there's no real problem. 
$(\flat)$:  I am sure there's no real problem. Therefore, since there is no problem that should be understood, it is a matter of course that nobody understands quantum mechanics. That is, since there's no problem, what we can do is only

This answer may not be uniquely determined, however, I am convinced that the above ($\flat$) is one of the best answers to Feynman's question ($\sharp_1$) and ($\sharp_2$).
The purpose of this lecture is to explain the answer ($\flat$). That is, I show:
If the reader knows quantum mechanics a little, it may be recommended to read the following references (before reading the blog):
[1]:  S. Ishikawa, “A New Interpretation of Quantum Mechanics,Journal of Quantum Information Science,” Vol. 1 No. 2, 2011, pp. 3542. doi: 10.4236/jqis.2011.12005 ( download free) 
[2]:  S. Ishikawa, “ Quantum Mechanics and the Philosophy of Language: Reconsideration of Traditional Philosophies," Journal of quantum information science, Vol. 2, No. 1, 2012, pp.29.doi: 10.4236/jqis.2012.21002 ( download free) 
[3]:  S. Ishikawa, “The linguistic interpretation of quantum mechanics,”arXiv:1204.3892v1[physics.histph], (2012) ( download free) 