Masaaki Yoshida's book "Hypergeometric Functions, My Love" is packed with many colorful passages. For example, opening at random I find:

"(Do you think I should write $R^{(A)}_b =P^{-1}R^{(H)}_a P$? The notation would smother you!)"

But I think my favorite is:

"I believe that developments of mathematics are made by generalizations followed by specializations. You should jump and fly like an eagle and then fly down toward a game. To establish a story of modular interpretation of $X(3,6)$ we must jump at least as a grasshopper."