Give it Focus
No one is impressed by a presentation that rambles. Rambling happens when the speaker is both self-indulgent and unorganized. Your purpose and prose must be specifically directed to interests of your listeners or they will mentally shut you down. Even if you hit upon a topic of interest, you will lose them quickly if they can't follow the logic of your ideas. Outline the structure of your presentation in a way that people can follow easily. Research your audience to make sure the topic is truly of interest. Promoting the benefits of beef at a vegetarian conference will likely empty your venue no matter how strong your passion for steak.