There's a fine line between "enough drugs to make the pain go away" and "few enough drugs that your brain still functions well enough for work", and it's yet another of those spoon management-style balancing acts that those of us with chronic health conditions just have to manage. You learn how to do it by trial and error, and try not to mess up. I erred on the side of caution, figuring that getting the pain down to a manageable level was a better idea than getting rid of it completely and being all... mellow... yeah... as a result. (Where " all... mellow... yeah..." is a reasonable approximation of the effect that the heavier opioids have on me.) I've been to work, and taught obnoxious kids, and not lost my temper even though at least one of them was being willfully stupid for a large amount of the time. But now I am completely wiped out.
Don't expect any coherence out of me tonight. Too sleepy.