“In war everything is simple, but the simplest thing is difficult.”Lev Tolstoi · Război și pace · 1869 · Volumul 3, Partea 2, Capitolul 18
The simple plan in theory gets bogged down in the complexity and chaos of practical execution.
Tolstoy notes the gap between simple plans on a map and the real chaos of battle. A general may say 'attack at dawn,' but on the ground, soldiers are tired, orders get lost, weather changes. What seems simple in theory becomes nearly impossible in practice. For example, a military maneuver that takes an hour on paper can fail due to mud or panic.
Why it matters This phrase helps you be realistic when planning: any simple project hides unforeseen difficulties.