I don't know anyone with a serious peanut allergy. If you suffer from this type of allergy, how do you prepare for a flight?

From my point of view of near total ignorance on the subject, based on this passenger's course of action which essentially removes peanuts from the cabin it sounds like peanuts should be banned on board. Yet no airline or regulator has done that. And I am sure many people are bringing on board products containing peanuts or tree nuts. I am quite confused....