The final third of Dr. Martin Luther King, Jr.‘s keynote address during the 1963 March on Washington–the actual “I have a dream” portion, from which the speech now derives its name–was famously improvised on the spot. If you re-watch the actual video of the speech above, you will note that right up till about the 12:03 mark, he is reading carefully from prepared notes. The first two-thirds wasn’t a flop by any means–he got raucous cheers during the “bad check” analogy at about 4:27–but otherwise he was finishing his speech with only tepid, polite applause. It certainly wasn’t a speech anyone was going to remember a year later, let alone 60. He knew he needed to get the crowd back, if for no other reason than to keep the pressure on Congress. So he did the one thing that, in 99.99% of cases, a public speaker should absolutely never do–the one thing that fills you with dread whenever a Bishop or Stake President starts to do it at the end of a meeting–because it’s almost always a sweaty, embarrassing flop:

He improvised.

From about the 12:12 mark on wards, you can see that Dr. King is no longer reading from prepared notes, because there are none. If you pay close attention during this section, you will note that he frequently pauses, not just for dramatic effect, but to buy himself a few extra seconds to think of whatever the next words are that are about to come out of his mouth–because even he doesn’t know yet!

And it works! He completely nails it! He not only wins over the crowd again, but coins his defining phrase, achieves instant-icon status, and exits the podium to the loudest cheers of the day.

This was, of course, the biggest speech of his life, on the largest stage of his life, before the most massive audience of his life, with absolutely zero margin for error. There were literally a million people there at the capitol mall that August day–that is, roughly equivalent to over half of Idaho, or a third of Utah–with just as diverse a crowd of people present! There were, for starters, legions of black people so beaten down for so long by segregation and oppression, that they’d lost all sense of hope, of “somebodiness,” of self-respect; Dr. King knows he needs to pump those people back up, to give them some vision to cling to, and get them fired up again.

But on the other end of the spectrum, there were plenty of much angrier black people there too, who considered Dr. King’s non-violent strategy to be a cop-out and a half-measure (Malcolm X was especially unimpressed by the march); Dr. King still wants to keep their energy and their engagement, but he doesn’t want that energy spilling over into violence, either.

He also knows that, though the white people actually present at the capitol mall that day are (mostly) sympathetic, that there are also tens of millions more watching from TV at home who were much more suspicious and on-the-fence about the civil rights movement, if not outright hostile (this is the same era when Ezra Taft Benson repeatedly called Dr. King a liar and a communist agent, by way of reminder). He’s trying to win them over too, yet without alienating his core black audience.

And again, he has no do-overs here, no second takes, no room for error! He cannot ask NBC to rewind the tape and let him try that again. And he’s doing this while trying to appeal to an absolutely impossible spread of audiences! All things considered then, the phrase “I have a dream” absolutely nails the sweet-spot between pumping up his allies and winning over his opponents. It is the one line everyone for sure can quote of him, and is the moment when he officially leveled up from leader to legend. It is not an exaggeration to say that the “I have a dream” portion is why MLK has the federal holiday, why he is on the stamp, why there is an MLK street in almost every major American city, why he has the monument in Washington D.C., and why there is a plaque on the Lincoln Memorial marking the very spot he delivered it.

And–I can’t emphasize this enough–he improvised it all on the spot!

But then, as our own scriptures read (we even drill our seminary students on it): “Neither take ye thought beforehand what ye shall say; but treasure up in your minds continually the words of life, and it shall be given you in the very hour that portion that shall be meted unto every man” (D&C 84:85). He had treasured up in his own mind the words of life, and it was meted unto him in the very hour he needed it most. That is not just a promise to the Latter-day Saints, but for all those who sincerely seek after righteousness.

But it has to be sincere, or it won’t work. (That honest sincerity, perhaps, is why Dr. King absolutely nailed his speech, while so many a Bishop has only fizzled out and fumbled their remarks when trying to fill the last few minutes of a sacrament meeting). May we go forth and treasure in our minds the words of life, as well–for we know not the day nor the hour when we will need it.