Basically the knowledge that we have if shared with others called teaching will increase the brain is ability to record that knowledge. The more often that knowledge is shared, the more likely our brain will remember it and our ability to teach will also increase.

The knowledge we have will be useful for others if we want to share or teach it so that knowledge can be beneficial to ourselves, other people can also benefit. I see many users are very enthusiastic in helping other users in various ways such as tutorials, suggestions, answers that are easy to understand and so on. And to date I have never doubted that a forum will lack users who can contribute and be useful to other users and I am glad they are called forum gems.