This is the part nobody tells you when you start.
Researchers (Vallerand and others) identified two types of passion in entrepreneurs. The difference predicts who burns out and who doesn't:
1. Harmonious passion = you love the work itself. The craft. The problem. The customer's face when it clicks.
2. Obsessive passion = you love what the work brings you. Status. Money. Validation. The identity of "founder."
There's a research by Harvard Business. 326 entrepreneurs found: those with high obsessive passion were significantly more likely to report burnout than those with high harmonious passion. Same hours. Same stress. Different fuel source. Different outcome.
This is the most important finding in the whole field, and almost no one talks about it.
