Simple rules guide innovative, intelligent responses. Comprehensive rules guide rote, routine responses.
A methodology's weight is a product of its size and ceremony.
If you find that your organization can't make the hard decisions that Scrum demands, then high-risk, uncertain projects have very little probability of success in your organization.
Process is not a substitute for skill.
The best way to get a project done faster is to start sooner
If you have unskilled people who work poorly together, no amount of process will save your projects.