In organic chemistry, we still teach the SN1 vs SN2 mechanism dichotomy as if every reaction cleanly fits one or the other. But in my lab work with alkyl halides, I've seen borderline cases where both pathways compete, and solvent effects often blur the lines. For instance, a secondary substrate with a polar protic solvent can behave more like SN1, contradicting textbook predictions. Does this mean our simplified reaction categories are holding back students from understanding real chemical behavior, or are they necessary scaffolding for beginners?