independent as a hog on ice
Unable to be controlled. The phrase was originally used in the sport of curling to describe the movement of the stones on the ice. I want to keep this meeting from happening, but it's independent as a hog on ice now, with so many people involved. I worry about my daughter's rebelliousness, but she's as independent as a hog on ice—there's no stopping her from doing what she wants to do.
independent of
Excluding (something); without taking something into account. My contract was written independent of overtime—I got a higher base salary instead. I need you to make a decision independent of your personal feelings on this issue.