I've lived this long because I didn't die. Dirk Jan Struik More Quotes by Dirk Jan Struik More Quotes From Dirk Jan Struik Mathematicians grow very old; it is a healthy profession. The reason you live long is that you have pleasant thoughts. Math and physics are very pleasant things to do. Dirk Jan Struik healthy math long Mathematics is a vast adventure; its history reflects some of the noblest thoughts of countless generations. Dirk Jan Struik education math adventure