数学不是沿着一条清理干净的高速公路小心翼翼地行进,而是一次进入陌生荒野的旅程,探险者常常会迷路。
Attention is the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought.
"Every story is a journey, and every journey changes the traveler."