The most painful thing about mathematics is how far away you are from being able to use it after you have learned it.

The most painful thing about mathematics is how far away you are from being able to use it after you have learned it.

数学最让人痛苦的事情是，你学了数学之后，离能用它还有多远。

-- James Hansen Newman 詹姆斯·汉森·纽曼