If you watch an old movie about traveling in the old days you may see yaks being used. The yak is still utilized in many parts of central Asia. They are drafted for pulling heavy farm machinery in planting and transporting large, heavy loads through mountain passes. The yak is able to carry quite a load and do so with little complaint. Some people complain about the slightest trifle and it grows quite wearying. However, there are times we have a large load to carry if not literally, figuratively. When times are trying, remember the words of the ancients. Live the verses of the Dao.