I think it's important to try to relate your topic to the experiences of your audience. Since everyone uses computers now, one point that I consider important is that in our modern world, whatever enthusiasm a person may have can be shared with others, literally all over the world. For example, quiltingboard.com now has nearly 120,000 thousand members! In our grandparents' time, the typical quilter might have a small circle of friends who shared the hobby, but in the middle of a project, they couldn't take a picture and ask thousands of others for input about whether this fabric would be a better choice or that one. We learn so much from each other, and benefit greatly from all the talented people who will take time to participate in sharing knowledge and enthusiasm.