"Not exactly. The theorem says that you can't coherently expect to do worse on average by making more observations. You never expect to lose more factors of two in total expectation, or on average. You might get unlucky and lose some in a particular case."
"And if you're wrong about what the evidence means, if you're wrong about the factors P(evidence ◁ hypothesis), you can see what's really there and update away from reality as a result, because you didn't correctly model the entanglement between evidence and reality."
"You just can't coherently expect that to happen to you. Any time you're like, 'oh no, I should not look there, that will probably lead me further away from the truth', you are doing something very strange and wrong, and in particular, you actually believe one thing, but believe you believe another. Like, you actually know, on some level or in some part of you, that really wizards wear red and clerics don't. But you think you believe, maybe because you remember reading it in a book, that clerics wear red and wizards don't, and you expect about yourself that if you check their clothing you'll do a calculation based on what you read in the book. So one slice through you, the part that really knows how things work, expects the verbal-calculations part of you to arrive at the wrong answer."
"What you do in this case obviously is say 'wait what?' and figure out what you actually expect and reconcile that whole thing where you actually believe one thing, but believe you believe another, and then go look. There's a whole separate skill and art form about that, which I'll maybe get to in a few days if nothing slows me down?"