Consider the eternal coming and going of folk.

On every road many are travelling one way and an equal number are travelling the other way.

It is obvious that, if they were all content to remain at the places whence they set forth, the distribution of the population would be the same.

Why therefore move hither and yon at the cost of much time and labour and money, since nothing is accomplished thereby?
We spare ourselves by being content to remain where we are.

We thereby have the more time for reflection.