Our feelings about coffee at Refinery29 aren't exactly a secret . From iced coffee to lattes, we can't get enough. And, of course, we aren't alone in our affection for the brew.According to a study by the Harvard School of Public Health , over half of adult Americans drink coffee at least once a day. And those people have, on average, three cups a day. The verdict is in: We love coffee, and we love a lot of it (the same study found that the U.S. spends $40 billion on coffee a year).Not surprisingly, those hoards of caffeine fanatics include some of our favorite celebs. And while their Instas may feel a bit unattainable (midweek, midday yoga and a private plane, anyone?), coffee is one relatable indulgence we can all enjoy. Indeed, mega stars need a cup of morning Joe like the rest of us.Click through to see 15 times celebs proved that, "but first, coffee" is as universal a sentiment as love itself.