From the 17th century, an anonymous writer talks about coffee:
“Coffee Collects and settles the Spirits, makes the erection more Vigorous, the Ejaculation more full, adds a spiritualescency to the Sperme, and renders it more firm and suitable to the Gusto of the womb, and proportionate to the ardours and expectations too, of the female Paramour.”
I’m too old, too impotent and too infertile to worry about all that stuff. All I know is that before my morning cuppa of Dunkin’ Donuts Regular, my attitude towards the world can be summed up thus:

Granted, the addition of coffee to my system doesn’t change my mood that much

…but I do go from murderous to simply dangerous. so there’s that.
And now, if you’ll excuse me, I’m off to the Keurig.