What motivates to Keep answering? high level posters?

I like being able to help other people. If someone has a question about something and I have some knowledge about whatever they are asking about, then I am more than happy to share that knowledge to help them out. However, I do like Polls and Surveys as well because the questions tend to be lighthearted and fun, so it's interesting to answer some of those questions, as well as reading other people's answers to those questions.