One of my all-time favorite sitcoms is/was the Cosby Show. I'm a child of the 80's, so I grew up on the parenting of Cliff and Claire Huxtable.
While there were 200 episodes, a few moments stick out in my mind: Cliff getting pelted with snowballs on the front stoop, Cliff and Theo learning economics with monopoly money where having a girlfriend takes all of Theo's remaining money [first episode], and of course, the Gordon Gartrell shirt. I often find myself thinking of one particular episode where Vanessa introduces the family to her new boyfriend, Dabnis Brickey, who happens to be significantly older than her. Not only that, but for the first time Vanessa divulges they've been engaged for six months. You can watch the introduction here. While this isn't necessarily a bad thing, Vanessa doesn't do that great of a job with the presentation of Dabnis, thus Cliff proclaims to Dabnis, "We just don't like you."
Watch this video to see how Cliff explains why the presentation is so important. Click here to watch it on Youtube [embedding was disabled], but make sure you come back!. If you want to go directly to the quote, fast forward to 1:15.
Jon Thomas draws an important lesson for speaking from an old episode of the Cosby show. While his concern is with preparation and rehearsal, I think you can also learn the importance of a good introduction from this clip.