I find myself doing something very similar when it comes to every day activities. Let's say I am searching for my missing sock and I have three locations to visit: A, B, C, with probabilities of finding my sock there: 80%, 15%, 5%. For some reason I keep wanting to search C, then B, before A. In my mind this kind of goes like this "let's make sure it's in none of the weird places and then I can be very sure it's in A and search it thoroughly". Empirically, most often if I just started with A, I would have been successful...80% of the time.

But to answer OP more directly: I feel that in most cases it's simple akrasia and the fear of succeeding.