Another before and after

Following this recipe, I just baked some carrot-muffins.

And as always, the butter was a little more than just soft. Why is it that butter goes from hard to melted in a matter of milliseconds?? I use the lowest level in my microwave to melt it. Put it in for half a minute at a time. And nothing happens. And then *BOOM* - it's all melted. The same goes for bringing milk to boil, by the way... (not in the microwave, but on the hob - leaving both the pot and the hob a pain to be cleaned). I wonder whether this is somehow possibly linked to my lack of patience...

Before

... and after