> Hey, how come I sleep *better* after drinking caffeine?

It could also be one's age and previous exposure. When I started drinking #coffee when I was in my early 40s, I could drink a pot of coffee as late as 21:00 and head immediately to bed afterward. No problem sleeping, despite a lifetime of such problems. Ten years later, I had to cut off both coffee and cola past 16:00 because even a small amount of caffeine would leave me with my heart racing and me not sleeping for most of the night, and the prior sleep issues had returned.