Today is World Stroke Day, which aims to raise awareness of the condition. Earlier this week I saw a conference keynote speech by Clayton Christensen, author of The Innovators Dilemma and a Professor at Harvard Business School.
He introduced himself by apologizing for hesitating while speaking because he'd suffered a stroke a few months earlier. In spite of this he was an engaging speaker - much better than the other professional conference speakers. His points came across so well because he's been thinking about them for decades and backed them up with well-researched evidence. His only concession was asking the audience to interject when he couldn't remember a word, but this made the presentation more interactive and memorable.
At the end of the day having something important to say always beats slick presentation.