I just don't understand this weight losing stufff

I broke my little toe about a week ago, so basically hobbling around in sandals because I couldn't wear a shoe, practically no exercise.
I had a big family gathering on Saturday(oh my word it was glorious) I had a couple of glasses of bubbly and a beer, I ate too much and I had CAKE.
I got on the scales Sunday and I have lost .6lb, after that long plateau .

Oh who gives a monkeys if I don't understand how, I just have.

Now to try and recreate so I can lose more