It's all apart of the new "needs" system for dwarves. Originally, dwarves would just go "on break" and loiter in a meeting hall every so often (I think determined by ethics, general stress, and if they are working with materials they like or not). Now, instead of a general need to blow off some steam, dwarves have specific and personal needs that must be fulfilled to avoid a debuff. They act very much like thirst and hunger now. Once the counter fills up, it queues up a "Worship!" job that will cause a dwarf to stop working. For example, a dwarf that is an ardent worshiper of some deity or another will need a temple to pray at. If they haven't had any free time recently that let them idle in the temple, when their counter reaches maximum they will gain a debuff and usually trigger a high priority "Worship!" job that pulls them away from whatever task they were assigned too. The same goes for other needs, but only some of them will force a dwarf to quit their current job and fulfill it now. These are the praying/watching performance needs. I have seem people with purple "Reading a book!" job, but those were designated scholars who do everything as a high priority task. Other needs are related to getting into fights (draft into militia)or arguments (argument lovers are good candidates for scholars!). There is also a "need to express creativity," where a dwarf needs to actually create an item that requires the creativity skill once in a while.