Remember the street car cannot turn out.

Framed as a practical reminder drawn from early urban life, the line uses the streetcar as a metaphor for constraints and right-of-way. A streetcar, fixed to rails, cannot swerve to avoid obstacles; others must yield or anticipate its limited maneuverability. Applied to human affairs, the admonition suggests adjusting one’s behavior to realities that cannot easily change—institutions, systems, or people with limited flexibility—rather than expecting them to accommodate you. It also implies prudence: avoid needless collisions with forces that are powerful precisely because they are constrained and predictable.