The biggest reason that PM works for me is because I find that I have the best understanding of something once I am able to teach or explain it to others. It offers those of us who want to give back and have the ability to do so, the opportunity to do so. To echo...once I see how other's would solve a problem, if my solution hasn't been offered up yet, then I throw my 2 cents in. Different solutions coming from different people of different experience levels can lead to different outcomes for whomever posts the question. Just being to see a solution from different levels might even help you solve other problems or make your code better in ways you hadn't known even existed.
And yes it can still be intimidating to post sometimes, just remember that whomever is answering you was at some point where you were and needed a similar questioned answered that they were apprehensive about asking. And the same holds true for the other direction, you can help people who may be apprehensive about asking a question. And as long as you answer it in a way that's not demeaning or derogatory, it keeps the demeanor and the standards for answering questions high, which I think is something PM wants to be known for.
