My first memory of drinking coffee is when I was under 7, I think. I would take a glass of water and a cup of very sweet coffee and drink out of both at the same time with straws. The thermic shock and the contrast between the strong sweetness of the coffee and the neutral mildness of the water made it delightful. I would never dare to do it again and ruin that memory with what would probably be a terrible experience. Now that I'm nearing my 40s with maybe 30 years of daily coffee drinking behind me, and my blood pressure soaring with the help of high levels of stress, I wonder if I should have started so early. Of course, being Brazilian has something to do with it, as well as with my coffee-snobiness (as a friend recently put it when I was explaining which countries served the best coffee, and what was the best type of coffee to order in each country).
The reason for me to dwell on coffee is because for me cafés and coffee are undistinguishable: I go to cafés for coffee, and I drink coffee to go to cafés. I always feel as if I were cheating when I, for example, have tea (or, worse, herbal tea) at a café. Coffee is for me a drug and that makes cafés into some sort of bohemian den where people share a common vice. If you don't do it, then don't go there.
Sometimes, you can't have coffee at a café: blood pressure alarm, 6th cup of the day and it is 7pm, no proper sleep in the last 3 days, terrible coffee, already time for wine etc. It can be acceptable in the same way that one will accept an alcoholic gone sober but not someone who doesn't "like the taste of alcohol". Tea drinkers should go to tea houses.
In Rio de Janeiro, the cafés-for-writing-and-working (and drinking), as they existed in the first half of the 20th c. and before, came back in the 90s. At that time, I elected a 24h-café for reading and working. It was called "Letters and expressions". It soon became known as "Letters and depressions" as it became kitsch, sad and empty. I have installed my office in many other cafés since.
In New York, it took me a while (2 years, actually) to find my working café. It was close to my 2nd house, on the Lower East Side. I liked it because the coffee was good, other locals worked there habitually, and it had a good mix of people and activities. People would work, talk, take out, stay in for hours etc. but it never got unbearably full. It had the exact amount of movement and calmness to make writing possible. I wrote my qualifying exams and my prospectus there, even as my stomach protested violently against the ridiculous amounts of coffee I was drinking. I would sometimes have to resort to herbal tea… (shame!)
I have just moved again, and changing cities sets the challenge of finding a new café. I suppose I will feel a little homeless until I do.