A meret is a 'mystery beret'. I don't know why it's a mystery, that's something you should ask the woman who created the pattern, which is over here. It's not truly Fibonacci, though, as I ran out of the pale blue yarn and so finished the thing in purple. You probably can't see the different colours in the pictures, as it's hard enough to see them in real life and with the sun on the balcony, I'll be surprised if you can even tell that the hat isn't white!
This is ridiculously easy to make! I knit most of the thing on my circular US8s, because they're my shortest and I hate knitting across double pointed needles. I did eventually need to switch over to my US7 dpns, after I started decreasing to the crown. I should've done the ribbing on smaller needles as it's a little loose, but I really didn't want to ... mostly because I started off that way and had to restart about five times because I kept messing up the ribbing across the needles. I may make some more of these as gifts.