A mathematician is a device for turning coffee into theorems. It is disgusting to note the increase in the quantity of coffee used by my subjects and the amount of money that goes out of the country in consequence. Everybody is using coffee. If possible, this must be prevented. My people must drink beer.
Caffeine is an adenosine antagonist.
It acts at adenosine receptors and blocks them, causing adenosine to circulate longer in the body, increasing its stimulatory effects. It increases the output of epinephrine and norepinephrine from the adrenal glands. It is a GABA antagonist. Caffeine takes effect about five minutes after ingestion, with serum levels peaking after about 30 minutes. The body takes three to six hours to metabolise and fully excrete the caffeine.