The Great Discontent did a great job on this interview with Merlin Mann. There is a lot worth quoting here but this passage really resonates with me.
"Over the years, I’ve learned to be a little bit easier on myself while simultaneously trying to be more realistic about what I can actually do. I think a lot about do-ability with whatever silly project I want to do next. I don’t think about whether something is easy or not: I think about what trade-offs I have to accept in order to do it well, on time, and on budget."
I still find saying "no" and making hard decisions about what projects to take on extremely difficult. Merlin was the first person that confronted me on this issue and I'm grateful for that. My own neurosis aside, this is a great read.