Thanks Carol for your comment and sharing your own story. I’ve heard of caffeine toxicity and overdose before, but I never heard of the kind of the lasting effects that you described! That’ll definitely make me more careful in the future about my own caffeine consumption!
By the way, I did actually do a repeat study recently with a much more detailed analysis (and also including alcohol and exercise). You can find it here: https://betterhumans.coach.me/the-effects-of-caffeine-alcohol-and-exercise-on-sleep-analyzing-the-surprising-results-117330af2480