Hard work pays off.
Every speaker was assigned a coach. And I didn’t hear of any report where the speakers dismissed the offer. They worked, reworked, and begged for more. My speakers estimated they spent somewhere in the ballpark of 100 hours preparing for their 18 minutes on stage. That doesn’t include the day of the event, of course. That’s approximately a 300-to-1 ratio of preparation to performance. Few business presenters will devote that kind of time, but given the stakes, maybe they (you!) should.
The audience likely has no idea when you miss your content.
Since I had seen many of the speeches prior to the day of the event, I know what was supposed to be there and what was off script. For the speakers I coached, I was sitting backstage reading a script of the intended speech (I was also the slide advancer, sequencing the slides in time to particular points in the speech). I was probably the only person in the building besides the speaker who knew the words coming off stage were NOT the words that were on the script. A couple of times, it was a humorous difference. A few times it was seemingly headed into the abyss. But none of the time did the audience know it wasn’t planned exactly is it was told. The key is to not appear to lose your spot. Pauses are never as long as they feel. And in one case I knew my speaker had lost her place when the audience was feeling the emotion of the moment and never noticed the pause.