I remember that there is a phrase with the word
whims that goes about like this: "I don't want to be reliant on someone else"
Does anyone know what that phrase is?
It's most often used not to express reliance but that someone is bound to carry out someone else's wishes, however trivial they may be. I can't think of a set phrase but it may help you to know that the most common collocation (after a) is with every. Here are some examples from COCA:
I didn't notice you were after the plural whims, in this case there is a phrase subject to the whims of, for example: