Something in Font last weekend got me thinking. If the hardest move on the problem is the very first one, and you can't get it, are you more inclined to give up? If the hardest move is near the top, you might be thinking 'so close, can't give up now!'
This occurred to me when watching someone else, although when I think about whehter it applies to me, it's less clear cut. If the critical move is near the top, it *might* give me psyche to finish it as I'm nearly there, but on the other hand I might say 'sod it' as I don't want to keep falling off from there. Conversely, if the hard move is the first one, I can bounce up and down all day without worrying about broken ankles or spotters etc.