Because I've been doing a lot of that.
Remember, this is the REAL site. We're not asking "seed" or "sample" questions here. There are enough people on this site (and a lot more coming) that we don't need seeders, per se. It would be very bad for this site if it was loading up with questions, just for the sake of asking questions. There are real people putting real effort into answering your questions.
Please use this site is to ask real questions about problems you actually have.
In terms of how to ask, if you have a specific question, ask a specific question. If you think your question applies to a more general case, include that information, too. Any additional information you provide in your question is helpful.
I was under the impression that was fine, I'd recommend leaving it a while before answering though just for the look of it.
I personally asked real problems I had but that I now resolved.
So I know the answers to my own questions, but they are real problems I had, they are not questions I made up just to fill the website.