You cook for your girl but forget to wash your hands after handling jalapenos. Then decide to have sex with her. Thus spreading that jalapeno to her vagina causing burning pain.
When you think when you did or are doing something you are doing a great job. But in actuality you are terrible at it.
The Gordon Ramsey Effect is when you think your great at something but your bad at it. Here is a a sentence describing it: “I thought when I sang I was great at it. But my instructor said I was trash...”