"Questionable Assumption Loophole: We make assumptions that influence our habits--often, not for the better--and many of those assumptions become less convincing under close scrutiny. A reader posted a good example: "I set up weird mental blocks around my time. For instance, if it's 9 a.m. and I have an appointment at 11 a.m., I'll think 'Oh, I have to go somewhere in two hours, so I can't really start anything serious' and then end up wasting my whole morning waiting for one thing to happen." Our assumptions sound reasonable ... but are they?"