Correct me if I'm wrong, and when I checked something on wiki (granted it's wiki) it kinda confirmed it, but when you look at what it had for something called "bonk training":
Bonk training
"Bonk training" is an exercise program designed for weight loss. It suggests the following strategy on an empty stomach the first thing in the morning, when glycogen store levels are low: consume coffee or caffeine equivalent to 2 or 3 cups of coffee, run or cycle at a casual pace (60% of
max heart rate) for 20-90 minutes, have a normal breakfast right after exercising. Proponents claim this will force the body to "bonk" shortly into the exercise, and subsequently burn more fat to generate the energy. It is not clear how medically sound this idea is; exerting too much energy and "bonking hard," or experiencing severe
hypoglycemia, can be dangerous.
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It seems as though if you start the ride off low, you CAN bonk out pretty early on, "newb" or not.
I believe I had bonked on a commute once on a particularly chilly morning in Feb, just after the halfway point (about 10 miles in), when everything, EVERYTHING, was gone. I had to stop, sit on the side of the road, and eat some of my lunch I pack and drink some water and just wait.
I was able to get back on and ride, albeit very slowly and very very tiredly (is that a word), to work. Long morning. That last climb on my commute was miserable that day.