Here's kind of a good example of the brain malfunctions associated with MS. It's a bit of a complex tale, so bear with me.
Some time back, my wife's friend had given her a copy of the movie series, Revenge, season 1. There were supposed to be 5 disks, but there were only 4. After watching number 4, we went to the video store to find number 5. Turns out we had to buy the entire 5 disk set in order to see number 5. Okay. The woman in the store said we could buy the 5 disk set and then bring in our 4 disk set and return it and get another 4 disks (of anything) for free.
Well, the day of this transaction arrived. We drove down to the video store, but then I realized, while still sitting outside in the car, that I had brought the set with 5 disks rather than the set with 4. Oh no! I've brought the wrong set. We'll have to do this another time when I can bring the original set that lacks disk 5.
My wife is sitting there listening to me, and then just kind of staring me, as if I'd gone crazy. I can see that she's actually starting to get angry.
"What are you talking about!"
I explain the situation again.
She stares. Then grabs the package from me, takes out disk five, and hands the package, now containing 4 disks, back.