Conversion-shmersion

I tried a new recipe tonight (yet again) and yet again I got it wrong. The sauce called for 60 ml of heavy cream. The grocery store I went to sold the cream in 20 cl containers. In the midst of losing the feeling in my arm because the basket was cutting off my circulation (because I did not have a 50 cent piece to be able to rent a cart) I got the cl and ml confused. So instead of putting in 60 ml of cream, I put in 600 ml (= 60 cl) of cream. That would be the US equivalent of adding 2 1/2 cups of cream instead of just 1/4 cup. Luckily Kyle will eat anything and the meal just tasted very rich. And we can't seem to figure out why we keep gaining weight...