My point really was that these fluctuations in weight don't necessarily mean anything. The problem is more likely to be our expectation that weight loss should happen in a strict linear progression rather than fluctuate up and down a bit.

I'm curious, why do you find it discouraging? At one point in my journey I stopped weighing myself entirely, even threw out my scale but stuck with the plan. After 2 years I had lost 30 pounds and this was after I had already lost 70 pounds. Maybe it won't work for you but it definitely works for me.