I've found it helpful to distinguish between errors that are program bugs and errors that are conditions of the outside world (network errors, invalid data, etc

I've found it helpful to distinguish between errors that are program bugs and errors that are conditions of the outside world (network errors, invalid data, etc). I think it depends somewhat on the kind of software you're writing. Being very careful with errors is quite handy for a long-running server processes; maybe (maybe!) not so worth it for a program that starts and stops within the attention span of a single user.