Learning research tells us that the time lag from experiment to feedback is critical.

I mean, source code in files; how quaint, how seventies!

How good the design is doesn't matter near as much as whether the design is getting better or worse. If it is getting better, day by day, I can live with it forever. If it is getting worse, I will die.

I tell people to start implementing when they are pretty sure there aren't more important stories out there. An iteration's worth of data is worth months of speculation.

I don't like the feeling, but I've got to say that a little fear makes me a more focused, more responsible programmer.

A plan is an example of what could happen, not a prediction of what will happen.

If you're having trouble succeeding, fail.