What’s the Most Powerful Lesson You Learned

Luis, it depends. I learned many powerful lessons, and all of them with the right timing and the right circumstances. In this particular moment and this specific situation and context, they were powerful. Some of them changed my perspectives, some my behaviors, all of them made me stronger. The same lessons could be meaningless for others.
Examples: 
- my decision to start a PM career instead of continuing in technical fields after successfully running a major project
- starting a PMO and running it for five years, by changing and adapting its purpose and mission and focus every year.
- acknowledging after three years that my project budget ran out after the first year (which at this time nobody cared about), and still surviving and seeing the project being continued and the customer pay for it