Question 1171308
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The proofs are the Soul of Mathematics and a joy for those who loves it.



The rest are the Tools for all others.



The true of life is that people are able to learn new conceptions till some threshold age, only.


After that, they only can to refresh their knowledge --- or to teach younger generations . . . 



It is a common true.

Probably,  exceptions are possible,  but I do not know about them.



Nevertheless, &nbsp;studying something and stretching your mind is &nbsp;<U>USEFUL at any age</U>.