Tom DeMarco is a fantastic author. His book "Slack: Getting Past Burnout, Busywork, and the Myth of Total Efficiency" is incredibly helpful if you're on a team that faces anything listed in that subtitle

What did you get out of these books?

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

Also an important takeaway from TMMM: people were having the same problems and trying the same approaches to solve them over 50 years ago.

A much better understanding of what it means to manage software engineering projects and work within a software engineering organization.

These understandings are valuable as an individual contributor: you are more self managing, which increases your perceived value (in healthy orgs), and are able to understand the machinations of a software org, which is good for your sanity and effectiveness.

mythical man month : “adding resources to a late software project only makes it later”, and gives you an authoritative reference to throw at everyone who hasn’t read it and thinks that “hey if I give you double the headcount can you finish the project in half the time?” It happens a lot in real life :/