In The Autobiography of Benjamin Franklin, Franklin seems to be saying, it's cool to be ambitious, but only up to a point. It's fine in the private sector, or in business, as long as you're using ethical practices and participating in healthy competition. After all, ambition's a natural part of human nature. But Ben Franklin thinks it's not cool to wear your desire for self-promotion on your sleeve, or obsess about getting promoted. Franklin says, if something really matters to you, you should be able to put your ego aside. When good career things happen, you should be grateful, humble, and modest. Don't seek out or ask for promotions or raises; just do great stuff and you'll get recognized.
By acting like he's not ambitious, Franklin actually achieves all the things he's secretly ambitious about.
Because Franklin honestly doesn't seek out higher status and praise, but is content to be humble and work hard, he's rewarded by the kinds of accolades that less-qualified schemers only hope of achieving.