One data point: I can drink 3 espressos at midnight, go to bed and fall asleep. Apparently I'm immune to caffeine which is both good (I can have a coffee at any time of the day) and bad (if I'm sleepy and I have to drive a coffee won't wake me up.) Maybe I also won't get any of those exercise performance effects.
Have you been diagnosed with ADHD? Caffeine has a similar affect on one of my children who does have ADHD. Not that we're giving him espressos at midnight, but during the day a caffeinated beverage will slow him down similar to a small booster dose of adhd medication.
Conversely, amphetamine relaxes me, lowers my blood pressure and my pulse rate by 15 bpm. Though I am very aware it would not let me sleep if I tried to.
(I do not mix the two. I was a daily two cup drinker until my diagnosis, now it's a coke zero once a week if any)
YMMV.