In general - answer. There are at least three interesting outcomes:

1. You provide exactly the answer the OP needs in a way they understand and make their day
2. You provide a completely rubbish answer and get a series of replies telling you about it
3. You provide a 'me too' answer that is ignored by pretty much everyone

In case 1 you have indeed given back to the Monastery in the best possible way.

In case 2 you end up learning something, and very likely it is a common mistake so those who come across your answer in the future benefit from it. You still give back to the Monastery, and learn something important along the way. Actually this is a pretty good way of giving back too!

In case three it's not apparent that you have made much difference, but even in this case it's likely that there has been a benefit - see below.</c>

To answer a question well can often take reasonable effort. You have to understand the question and very often that means considerable skill at reading between the lines. Often you need to take the OP's code and munge it into a form that you can actually run. You may even have to invent some sample data or do other similar things to get a good understanding of the question. All this effort is great for exercising your Perl and analysis skills. Along the way you may end up installing a module you've not worked with before or using a feature of Perl that you hadn't played with previously and discover a new tool. Very likely you will end up consulting some documentation along the way, so regardless you are likely to learn or refresh something.

In all three cases just the process of doing the groundwork before providing the answer will improve your skills as a programmer and your Perl knowledge. I guess this goes to highlight that one of the best ways to learn is to teach.