Fortune asked a wide variety of people what was the best advice they ever got. It’s remarkable how many credited a former boss.

Article: The Best Advice I Ever Got

Some of my favorites:

• Michael Bloomberg: Always ask for the order and when the customer says yes, stop talking.
• Tina Fey: Sign your own checks.
• Peter Peterson: Focus on things you do better than others.
• Nelson Peltz: Get sales up and keep expenses down.
• Charlene Begley: Spend a ton of time with your customers.
• Andrea Guerra: In your first years, don’t chase fancy titles; find people who can teach you something.