How to Say No to Projects and Invitations to Talk

Pods are like a filter, you can stop whenever you want. And most of the rest is noise I don't need to know about it. It's not that there's anything wrong with deciding to watch YouTube for an hour in the way that you go see a movie or something but it's that mindless automatic habit of doing it that I'm trying to fight against. But one thing that he wanted to bring up particularly to the two of us with our mixed roles as well as doing our work and having an academic sort of presence at our workplace was when do you say no? What's your approach to that and has it changed as you become older?"