I'd say part of it is your dealing with children sometimes. I know I'd get tired of dealing with (mostly) sr captains constant sickcations. Or new FOs who never had a job that required strict adherence to a schedule. Im shocked at how many guys plan on only doing 2 trips a month. I flew with one guy who would bid lines that worked christmas so he could sick it and get 2 weeks around the holidays off each year.

Add in problem child employees who cant work in a crew environment and i would go nuts.