[autoconfig]

It definitely is a stimulant:

> Caffeine is a stimulant, which means it increases activity in your brain and nervous system. It also increases the circulation of chemicals such as cortisol and adrenaline in the body.

https://www.betterhealth.vic.gov.au/health/healthyliving/caf...

I'm pretty caffeine sensitive and I get a crazy buzz from just one cup of coffee. It's not just not feeling tired, I literally get high.

[singpolyma3]

It's quite likely your outsized effect is more placebo than induced effect.

[autoconfig]

Extremely unlikely. Caffeine is one of the most studied substances on earth. It's not a secret that it causes a clear physiological response. There are tons of double blind placebo studies on this.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4480845/