I’m sure everyone’s either made a presentation, or seen a presentation, where things go well only for the speaker or speakers to end and open up to questions and be asked ‘weren’t you meant to talk about X?’ It’s easy to miss out a chunk of your presentation, just as its easy for an actor to miss out a page of dialogue in a play, and you might never realise or only realise at a point where it’s just too late.
But I’ve seen people become muddled in their own presentation, because they’ve said the wrong word. That shouldn’t matter. The structure and the content is what needs to be memorised, not every single word. The temptation to memorise is seductive, but having a good memory is not part of presentation skills. It can help us feel like we’re in control of the message, the audience, and the situation. But strict memorisation actually controls us: it limits what we can talk about, and prevents us from actually listening and responding, and we can easily be thrown off by an unexpected question, failing to remember accurately, or a change we didn’t plan for.
Preparation is absolutely critical to making a presentation good. Even if you think you know your subject well enough to make an impromptu four-hour speech about it (and I’m sure you do), it does not hurt to plan a structure where you organise your presentation into a logical narrative. If the subject is new, make sure you know a good deal of statistics or other information around it, not just the content you need for your presentation right now.
More important than memorising your presentation, is knowing it; what comes next, what’s the purpose of saying this, what feeling should I try to create here? People don’t want a lecture from memory, they want an emotive presentation – remember that!