if you offer wisdom from a third party, it seems less arrogant and more acceptable.
The size of your audience doesn't matter. What's important is that your audience is listening.
Because you’re such a good salesman, and if you go work for a company, they’re going to use you as a salesman. If you’re going to be a salesman, you might as well be selling something worthwhile, like education
An injured lion wants to know if he can still roar.
I've always admired people who are over-prepared.
Throughout my academic career, I'd given some pretty good talks. But being considered the best speaker in the computer science department is like being known as the tallest of the Seven Dwarfs.