When you leave here, don’t forget why you came.

The line is a compact admonition about purpose and integrity: entering a place—an institution, a meeting, a movement—should be guided by a clear “why,” and departure should not dissolve that original intention. It can be read as advice to resist distraction, complacency, or the seductions of status that can accumulate once one is “inside.” In political or civic settings (where Stevenson is often invoked), it functions as a reminder to keep faith with constituents and ideals rather than with expediency. More broadly, it speaks to personal resolve: goals and values should outlast the immediate pressures of environment and circumstance.