Who among us has not spent countless hours squeezing, rubbing, and smushing gooey substances like, shampoo, tooth paste, jam, butter, motor oil, or the foam of a nice latte between our fingers? If we could magnify our view and look deep within the substances we are handling what structures would we find? How, do these structures lead to the fascinating mechanical properties thinning, thickening, or viscoelasticity that we experience on the scale of our fingers. In this talk, I will focus on the behavior of dense suspensions of micron sized spheres or colloids that serve as a powerful model system capable of exhibiting many of these behaviors. I will describe our strategy for using custom devices to measure the macroscale mechanical response of the suspension while simultaneously backing out the stresses at the single particle scale using 3D imaging. The phenomena I will cover range from measuring the stresses surrounding defects in crystals, to uncovering the secret behind the shear thickening properties of Oobleck.