This phrase refers to misplaced allegiance, meaning that a person who places their trust or friendship in the wrong people and ignores or distrusts the people she should trust, "does not know which side her bread is buttered on".

lorax - It's not the Lorax. The Zooks in "Butter Battle" by Dr. Seuss eat their bread with the butter side down and the Yooks on the other side of the wall eat their bread butter side up. "Butter Battle" is about the Cold War.

You would create anti-matter.

you would also realize that you have waaaayyy too much free time

No, the odds are 50/50 that the toast will land with the buttered side up.

You put bread in the toaster and when it pops out you butter it.