If you need to learn something (e.g. you're taking a class or your supervisor wants you to learn something), then reading the documentation is a good idea. If

If you need to learn something (e.g. you're taking a class or your supervisor wants you to learn something), then reading the documentation is a good idea. If you already know the content, but accidentally made a typo and are trying to debug it, then reading the documentation isn't going to help. An error message pointing out the problem will help.