Maybe I was thinking of work because of St. Joseph, whose feast day just passed. We celebrate him as the patron of workers on May 1, but he always remembered as the saint for the working man or woman (as well as the patron of the Universal Church, unborn children, fathers, travelers, and immigrants, and of course the patron saint of a happy death, which some of the boring jobs have made me wish for).
As regards my chart, obviously jobs that are boring and difficult are the hardest, since they require the utmost concentration and ensure the least desire to concentrate. A job that's difficult but interesting can at least keep me engaged. One that's boring but easy I can fly through, the greatest danger being that I'll detach too much and make mistakes. And a job that's easy and interesting is the best, because that's easy money.
As I considered my chart, I realized that if we scaled to the boxes to the assignments I actually get by volume, it would look more like: