If the talk doesn't have an effect on you, it won't have an effect on anyone else
When I prepare for speaking, the first thing at the top of my list is excitement. I need to be excited about what I'm going to say. It's extremely important because this excitement is later going to be the counterbalance against fear. So, if I don't feel excited at the start then I would benefit from finding a way to reframe or change what I'm talking about.
Here's an example that's close to my heart, back in the day when I was studying Outdoor Recreation, we were asked to give speeches as part of our training requirements. Everyone quickly secured their topics such as the qualities of the new Macpac tent or cross trainers and other such entertaining subjects that could be easily skim read from a brochure.
To the surprise of the speakers, no one cared much for what was being said and this made everyone uncomfortable. Clearly, there was pain being experienced by both the speaker and the audience. So I asked my tutors if there were restrictions on the subjects, turns out there weren't and I was free to choose my own.
My first subject was child pornography and pedophilia in Asian countries, a very serious and sobering subject that held me accountable for respectfully delivering the content.
My second was the fascinating subject of spontaneous human combustion. I spoke about the candlewick effect versus internal combustion lacking an obvious or explainable ignition source.
Finally, I spoke about male rape statistics in Australia, where one in 13 reported cases of rape were males.
I found these subjects fascinating and I was genuinely enthusiastic to share what I had learned with my class. In addition, I didn't have the negative experience or responses that the other speakers had.
People listened with intent, they were receiving this information for the first time, and I was sincere with the subject. It was received with gratitude.
If you can't get engaged, excited, or enthusiastic about your subject then I wouldn't expect anyone else to and I certainly wouldn't hold it against them if they didn't.