I am thrilled to have this community and I have learned so much from so many questions and answers here. The previous responses touch on many great answers and I agree with them all. But, to me, the most important things that I have taken to heart from SSD are two concepts underlying the whole board that are constantly reinforced.
“There are naive questions, tedious
questions, ill-phrased questions,
questions put after inadequate
self-criticism. But every question is
a cry to understand the world. There
is no such thing as a dumb
question.” - Carl Sagan
I'm particularly impressed with this community and how the forum covers such a gamut of ideas with such relatively little judgement or ridicule. From entry level basics to advanced concepts, technical, fix-it questions to esoteric, philosophical ideas, practically everything that is posted gets a response in some form or another. Off-topic ideas are given links to other forums where the question can be more properly answered. Repeat questions are directed to links where the question may have been answered previously. In my opinion, this trust of support allows students with fresh perspectives to mingle freely with highly seasoned professionals who know the necessary steps to persue and avoid to succeed in this industry, and we all benefit in the observation of these interactions.
“If my hands are fully occupied in holding on to something, I can neither
give nor receive.” - Dorothy Solle
I have met many who hold their trade's secrets tight to their chest. I believe they think its their knowledge of how they do what they do that is attributable to their "success". I used to subscribe to that idea, thinking it was a necessary way to survive. That having more knowledge than another gives you a "competitive edge". Perhaps it's maturity, a greater confidence in my abilities, or just seeing the interactions here on SSD, but over the last few years I've shifted my notion to I think that philosophy is utter bullshit.
Much like what Fred and Mark refer to in their answer, I love discussing my craft because it simply makes me better at what I do. Sharing what I know and talking out ideas with others can obliterate my own ill-founded, preconceived notions, smooth out illogical thought processes, or confirm un-tested perspectives. If in the process of discussion I can do the same for someone else, that just makes my day. I've come to realize that it is not teaching a person to edit or mix that makes them an editor or mixer, it's how they apply that knowledge that makes them the professional they where meant to become. That change in perspective has been priceless.