I bet the day after subjecting yourself to lighting and other stimulations, you have a bad day. Often, we can get our brain to meet the task at hand but the fatigue manifests at a later time, usually the next day or that evening.

I disagree with the challenge your brain protocol. Minimal levels of stimulation are good but pushing is counter-productive in my opinion and the opinion of many experts.

You want to find the correct kind and level of stimulation to keep the brain engaged but not over-taxed.

My best to you.