The Lean Canvas (Ash Maurya, 2010) replaced 40-page business plans with a single page. Use it.
Nine boxes: Problem · Customer Segments · Unique Value Proposition · Solution · Channels · Revenue Streams · Cost Structure · Key Metrics · Unfair Advantage.
Fill it in 30 minutes. Update it weekly. The point isn't accuracy — it's exposing the holes in your thinking.
Next action
Turn the lesson into work.
Pick one concrete next step now, while the context is still fresh.