This trope describes any situation where a form of mild control, either magical or science fiction related, affects its subjects in such a way that they themselves are oblivious to the change in their thoughts or behaviour. To use a trivial example, if a hypothetical magic mind control spell that makes the subject think that the color 'blue' is actually 'red' we're cast, the subject would see blue things as red and would not think anything had changed. If they were mind controlled to find a certain person they previously hated attractive, they would simply find that person attractive and not notice that this attraction had apparently come from nowhere or consider anything untoward has happened. Equally for acts, if they are mind controlled to do things they previously would not do, they will not think anything is strange or amiss. Instead if they are challenged on what they are doing they will defend it as totally normal even if it is something totally outrageous such as stripping off in public.