You may have read or heard that I refer to myself as a "Mathematologist". Mathematology is the study of all things mathematical including: mathematics, history of mathematics, study of mathematicians, mathematical poetry, mathematics and religion, mathematics and psychology, math music, mathematical recreations, mathematical humor, etc.
So I wanted to include a book by Robin J. Wilson titled "Stamping Through Mathematics" - a book about stamps that honor the history of mathematics, mathematical ideas, and famous mathematicians.
So now we can include "stamp collecting" as part of the subject of "mathematology".
I also know that stamp collecting is not as popular as it once was, because nobody sends letter or postcards any more. I also know that (OK lets pull out our Venn diagrams) the set of mathematicians and the set of stamp collectors does not have a large overlap.
But I would venture to say that if you want to be a well rounded mathematologist you should check out this book.