From Benjamin Zander's effervescent TED talk:

"I'm not going to go on until every single person in this room [has] come to love and understand classical music. Now you notice that there is not the slightest doubt in my mind that this is going to work. It's one of the characteristics of a leader that he not doubt for one moment the capacity of the people he's leading to realize whatever he's dreaming.

I'm going to be weaving this idea into my upcoming talk at RailsConf.

I have a goal for my audience, and will show no doubt that they can achieve it.  Then, I'll make sure they do by giving them the means in my talk.