I find it most relevant to planning and prediction. It helps greatly with realizing that I am not an exception, and so I should take the data seriously.
In terms of things that changed when my beliefs did, I submit the criminal justice system as an example. I now firmly think about crime in terms of individuals being components of a social system, and I am exclusively interested in future prevention of crime. I am indifferent to moral punishment for it.
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.