I don't eat breakfast. I eat a huge meal right before bed. And most of your digestive system shuts down overnight. Thus as I get ready for my day, I'm digesting the meal and have all the energy I need.
The story behind the beginning of the "most important meal of the day" is interesting. Look it up sometime. It started with cereal companies doing a study of a couple dozen people. A few who ate breakfast could do a couple more situps in a given time period than those who didn't eat breakfast. That certainly has potential for bias, the study was done on far too few people, and really didn't focus on anything useful (not many people really care how many situps they can do). Somehow that one and only study morphed into something that schools promoted as necessary for proper learning. As of a few years ago, no comprehensive scientific study was ever done on the subject (of course one could have been done recently).
I'm not saying breakfast isn't important - it probably is. But when that phrase came out, there wasn't evidence to support it.