背景上文字是“Windmills of Your Mind”的歌词，喜欢里面层层叠叠，连绵不绝的意象，很象是古人所谓的“连珠喻”。读书走神时画了这串钥匙（“Keys that jingle in your pocket”），纸团上是Sting的歌，都是那时候常听的。《音频下载》
Round, like a circle in a spiral
Like a wheel within a wheel.
Never ending or beginning,
On an ever spinning wheel
Like a snowball down a mountain
Or a carnival balloon
Like a carousel that's turning
Running rings around the moon
Like a clock whose hands are sweeping
Past the minutes on it's face
And the world is like an apple
Whirling silently in space
Like the circles that you find
In the windmills of your mind
Like a tunnel that you follow
To a tunnel of it's own
Down a hollow to a cavern
Where the sun has never shone
Like a door that keeps revolving
In a half forgotten dream
Or the ripples from a pebble
Someone tosses in a stream.
Like a clock whose hands are sweeping
Past the minutes on it's face
And the world is like an apple
Whirling silently in space
Like the circles that you find
In the windmills of your mind
Keys that jingle in your pocket
Words that jangle your head
Why did summer go so quickly
Was it something that I said
Lovers walking along the shore,
Leave their footprints in the sand
Was the sound of distant drumming
Just the fingers of your hand
Pictures hanging in a hallway
And a fragment of this song
Half remembered names and faces
But to whom do they belong
When you knew that it was over
Were you suddenly aware
That the autumn leaves were turning
To the color of her hair
Like a circle in a spiral
Like a wheel within a wheel
Never ending or beginning,
On an ever spinning wheel
As the images unwind
Like the circle that you find
In the windmills of your mind
Pictures hanging in a hallway
And the fragment of this song
Half remembered names and faces
But to whom do they belong
When you knew that it was over
Were you suddenly aware
That the autumn leaves were turning
To the color of her hair
Like a circle in a spiral
Like a wheel within a wheel
Never ending or beginning,
On an ever spinning wheel
As the images unwind
Like the circles that you find
In the windmills of your mind
精巧细致（Subtlety）和质朴健壮（Robustness）是矛盾的，做信号处理时常有这感触。一个随便什么的曲线中，哪些成分（Component）是重要的呢？什么分辨率（Resolution）是合适的呢？如何定义价值函数（Cost Function）呢？苹果和桔子的权重（Weight）该如何分配呢？都是些难题啊。
