In this way, you know the details well enough, in order to speak about it before a mass and with authorization. But you do not select a topic that you are approximately too sensitive, because it lets you approach too emotional you to the topic with a realistic, rationally and in a separated way. Also you examine whether the topic would not be too insulting for even a section of the mass. There they are to debate after controversy to injure feelings or feelings of the people not, by penetrating personally received or their private life. Aim at a topic, which is present and disputed. If all people will agree with you in the mass of the listeners, it would not give a left debate, or no controversy caused in the first place. So where would you look for an interesting topic for a convincing speech? Are here some places, which could try you: Internet message Web site, in which there are much of daily events, newspapers with daily events and stories, books with interesting ideas, concepts or theories, films with interesting ideas, concepts or stories, your own life, in which any disputed topic was believed very strongly by you or somebody else lives, in which a contentious expenditure was believed very strongly by you.