I apply the concepts from MMM in professional contexts probably more than all other books combined. So many absolute timeless gems.

* No silver bullet

* 2nd system effect

* Mythical man month (adding people to a late project makes it later)

* "Question: How does a large software project get to be one year late? Answer: One day at a time!"

* Separate architecture and implementation

* "The Surgical Team" about technical team structure