My interaction with my dad (an SLE) illustrates this very well. I'll give one example, but there are several others.
My dad asks me to retrieve something for him -- it could be a tool, something in the fridge... some sort of object that I have close access to. I start to look for the object. I can't find it. A small feeling of panic sets in. "I
know it's here." I keep looking. Still can't find it. I return to dad, and explain to him very quickly that I can't find what it is he's looking for, even though I've looked. Slightly agitated, again, he explains to me in detail where I can find it. I think to myself, "I
just looked there, damn it. I thought I looked there, well, I guess I have to try again." I return to the area where the object is found, and try to incorporate the instructions he's given me. I'm trying everything I can to avoid returning to him empty-handed. After still struggling to find it after a minute or two, dad says my name in a very agitated tone, walks over behind me, says "Move." Then proceeds to grab the object in less than two seconds, "Right here, right in front of you!"
At which point I try to tell him "I looked there though!" to which he replies "Well, obviously you didn't look hard enough."