Bread has always been a fascinating subject to many quantum physicists/intelligent writers/suspicious dogs.
Whenever it has jam/cheese/ham/mayo etcetera on a side, that side always seems to be at the bottom of said slice of bread when it hits the floor.
However, this is only true if you spread jam/cheese/mayo or put ham on the right side.
Bread has a taste aspect to it, but also immense psychological value. 99% of the time, people will unconsciously only spread jam etc on one side of the bread, the only side that will fall on the ground.