Granniesunite
It means you'll not compromise. It's your way or not at all.
No, it means that when it is a choice of two things that are incompatible, you just have to choose one and give up the other. Either A or B or neither, but the person described, who wants both, will lose both.
In Aesop's fables is a story of a dog that is carrying a stolen piece of meat looks down as it is walking beside or crossing a stream and sees its own reflection in the water. Taking that for another dog carrying something better, it opens its mouth to attack the "other" dog and in doing so drops what it was carrying.