My maternal grand-dad was a big coffee drinker. He disliked Singapore kopitiam coffee as too diluted, preferred strong Javanese coffee from Indonesia – there was no Starbuck then in 1980s before he passed away at 90+ with no major illness. At that old age, his brain still could do speedy mental calculation (a la abacus) from Singapore dollars to Indonesian rupiahs.
The 21st century genius Hungarian Mathematician Paul Erdős (1913 – 1996) once said,
“A mathematician is a device for turning coffee into theorems.”
French people like strong Expresso and drink everyday Café au lait at breakfast, that might explain why France produces 1/3 of the Fields Medalists (Nobel Prize equivalent in Mathematics).