Generate a full detail guide on 'Strategic Quitting,' inspired by concepts from Seth Godin's 'The Dip.' The guide must be a decision-making framework. It should include detailed sections on: 1. The Psychology of 'Sunk Costs' and Why It's Hard to Quit. 2. How to Differentiate Between a temporary 'Dip' (a hard part worth pushing through) and a 'Cul-de-Sac' (a dead end). 3. A checklist of questions to ask yourself to make an objective decision. 4. How to quit a project or strategy gracefully without burning bridges. Please include a supportive disclaimer.