If you know what you’re talking about, there will always be more interesting things to say than you have time to say them.
The common approach is to try anyway and fit as much of it into the talk as possible.
And it makes sense, doesn’t it?
In a way, yes.
But then again, how well does it work usually?
It risks overwhelming your audience …
… or you run out of time on stage because it took longer than the speaker expected.
I bet you’ve seen it just as often as I have.
Ultimately, it means that either the audience or time will decide on what sticks.
That’s why I think a better approach is to do the exact opposite:
Put in as few things as possible.
Put in the things that your audience absolutely has to understand.
Start with only one thing.
(Yes, only one thing!)
What is the most important thing that your audience needs to understand?
And then put in the second most important thing.
And the third.
Until you hit the time limit.
That way, what will be left out, will be the least important things (obviously) – and you’re in control of what that is.
(Btw, it will also usually make for a much more focused and engaging talk.)