"You have to accept upon yourself the yoke of Torah!"
This sounds like we are to submit ourselves to a miserable life, burdened with something needlessly weighing us down.
The animal has to put the plow with or without the yoke. Man has to eat. Eating means someone had to plow. Life requires doing, effort, going out into the world and finding our livelihood. If we go out in an entirely physical way, we will become burdened by our struggle. But if we go into the same world for the same purpose but with Hashem's holy Torah guiding us, we not only will not be brought down by the world, we will actually pick the world up.
Before the yoke was invented the animal had to pull the plow with its neck and teeth. Ow! Then some wise farmer saw that the cow would do a better job and be happier too if it used its shoulders to pull the plow instead of its teeth. So this wise farmer designed a way to attach the plow to a yoke that fit over the cow's neck and rested on its shoulders.
How do you think the cow felt with its new yoke? It might have been the first time a cow ever said, "Barouch Hashem!" He loved it. And this is what the yoke of Torah does for us when we use it in the proper way.
The Torah comes to increase our joy by giving us spiritual tools that we can use to elevate our awareness of Hashem's ever present, but oh so very hidden, Presence.