I eat dinner leftovers for breakfast and I had a few people say that was bizarre. How did this come to be? Is this part of an agriculture society?
hi! Could you specify which culture/country you're referring to? That will help focus the answers. Meanwhile, you can get started in the FAQ
The standard "bacon and eggs" breakfast was the creation of advertisers in the early 20th century in an attempt to simply sell more bacon, which was once considered more of a scrap meat.
http://www.americantable.org/2012/07/how-bacon-and-eggs-became-the-american-breakfast/
As far as breakfast cereals are concerned, this essentially came about in the early 1900's. Kellogg was a Seventh Day Adventist (whose traditionalist members tend to be vegetarian), so he and his brother created a line of foods that non-meat eaters like themselves could eat.