Although there are beverages with more caffeine, coffee really seems to have that certain kick for me like nothing else. Coffee has hundreds of substances in it. Awhile back I did a little research, they decaffeinate coffee by rinsing the beans in a substance derived from bananas. Decaf has about 5% as much caffeine as regular. I find it still gives me a boost, though not as wired. I don't normally drink decaf.
I brew it really strong, let it cool, then store it in the fridge. (It's not as bad as letting it sit on the burner for hours and ferment, still tastes fresh to me). I usually only have one cup when I wake up, occasionally one more mid-day, and rarely one after dinner. I mix a lot of milk in it, so it's kinda a homebrewed cappuccino.
As far as expresso, I heard although it tastes a lot stronger than regular coffee, it actually has less caffeine since the beans are roasted longer for the darker taste. Makes sense to me. Maybe the concentrated brewing process offsets this. It's effect on me is not nearly as strong as what I normally drink.
I find it's great for curing an occasional headache (possible withdrawal symptom?)
Over the years, I've built somewhat of an intolerance to it, if I couple it with any other type of caffeine (cola, tea) in the evening, it takes me a lot longer to fall asleep. If I drink 2 or 3 cups, or more in a short time span, chances are I'm going to be HIGHLY irritable, and it takes a few hours to wear off.
I don't really consider it a performance enhancer for myself, Years back they strongly advised against it before exercise. I don't know about now, I guess not, due to the influx of 'energy drinks' containing caffeine, effedrine. If I drink it just before I ride my mtn bike, I find my endurance suffers. I also tend to avoid it when I'm already stressed out.
Like a lot of questionable substances, I think it's ok in moderation. I do like the feeling of that one cup in the morning.
A little history, (I'm a little fuzzy on this) folks were known to frequent coffee houses (days of early America?). They would drink it all night long until they hallucinated.
One of the best brews I ever had was when I brought back ten lbs of Jamaican Blue from a trip. It was a bargain at 3 dollars a lb.
Little known and seldom used facts by Cliff Claven:)