It can come down to how well you know your topic. If the presentation was on how to make a cake then my mother would be able to take to the stage and do the who

It can come down to how well you know your topic. If the presentation was on how to make a cake then my mother would be able to take to the stage and do the whole thing with zero preparation. She would pop the recipe and the method notes up on the big screen and that would be it. Myself, because I actually would have no idea what I would be doing, I would make up slides for each step in the method summary and still be reading them. Again, my mother would not have to refer to what was on screen. Actually there is lots of science and craft and history and plenty else in cake making, again, my mother would be able to do all that with open ended questions. I think that if you have been working with the same clients and the same code for the last few years then you too can present without the presentation, to keep the audience captivated and learning. Vision, focus, enthusiasm all comes into it. The other part is having presentation skills. Who really likes standing in front of a crowd? This can be learned, however some people go to posh schools that emphasise public speaking and other people go to schools where this is not something that happens. It is a lot easier to stand up and talk in front of a crowd if you have done it every week throughout your childhood than if you have not done it before.