The people who post most regularly tend to do so with only the desire to
help others learn.
Some, like yourself, seek to learn by the helping, as well as simply receive help. (Actually, the desire to learn through helping shouldn't ever go away.)
Others, like myself, aren't too worried that someone is going to post something so amazing or un-obviously clever that we'll ever be tempted to pass it off as our own. The unfortunate fact is that most stuff posted for help is really very poorly written -- which is the cause of the problems and simply a matter of needing to learn more.
No artist starts out making great art. He starts out making really crappy art, and practices until it becomes great. The same is true in all disciplines. Especially programming.
Part of the hacker culture is to share and help. Company non-disclosure agreements and the like certainly exist -- and any programmer worth his salt honors them (it isn't hard to ask questions that don't reveal obligatory secrets).
While the following is written for new posters, it illuminates the mindset of frequenters as well:
How to Ask Questions the Smart Way
http://www.catb.org/~esr/faqs/smart-questions.html
It is worth the read by anyone.
Experienced programmers are often gratified by helping others to think about computer issues the right way.
Hope this helps.