Tactile and visual memory
As onerous as it might be, the very process of filing things physically helped to organize your work life and your life life. In the same way people acquire and retain information better when handwriting rather than keyboarding, manually going through papers and positioning them in a physical space reinforces the information.
For those with a tactile or visual orientation, placing documents in a particular place imprints them in your brain: the folded corner, the weight and smell of the paper. “I remember putting that memo with the chart here in the back,” you’d think to yourself, making your way to the rear of filing cabinet K-M.