There are eight yogas by which a person may perfect their practice of Grihastha: satisfaction and dissatisfaction, importance and unimportance, honor and dishonor, gaining and losing. Only when a person has yoked themselves to all eight can they begin to understand the purpose of their training.
How can a person truly understand what it is to be important - without having been unimportant? How can a person understand what is beyond being important or unimportant, without knowing both importance and unimportance? The yoke results in sufficient strength of mind, body and heart to become so enlightened, and thus to bring an end to all distress. It is the yoke which permits the understanding of things like Love, and Duty.
The ox does not understand the plow it is yoked to, nor even sees the seeds planted by the farmer behind it. It is unlikely the ox would understand the seeding, even if it could be seen. Imagine, then, how better the ox would bear the yoke if it lifted its head from the ground for only a moment and, understanding the nature of its world, understood its own simple nature as well. The act of understanding would be transitory, for in that moment, the ox would become something very much more complex.
How does a person yoke themselves to these? They bear them, not as an ignorant ox, but as an athlete of the spirit.