Clearance, Interference - pt. 2

I've managed to complete only 2 circles on these themes, despite the fact that the total number of problems is only around 70 or so. These are, by far, the most difficult themes for me to grasp, but I'm starting to get a handle on them. It's gotten to the point where it takes me 2 weeks to complete 7 circles for a theme grouping of around 70-120 problems. So, with 377 problems to go after this week, I will be working about 6 - 8 more weeks before I begin using the complete book as a problem set. Then, 10 weeks after that I will be done. So, we're looking at about the end of summer for me to finish (just in time for a new arrival at my house - late nights, bleary eyes, the whole bit).