Your shoes would be hard to fill. As we continue our April theme of being bold about what makes you unique, I encourage you to take some time to reflect on how you've succeeded so far. Even accomplished leaders sometimes take their distinctive skills and abilities for granted.

What themes do you see in your success story? Think about the kinds of work that you typically get asked to do. That's a good indicator of your strengths. What have you heard others say about why they value you work? What skills and perspectives do you have that would be hard to replace?

For inspiration, here are some stories of women with humble beginnings whose boldness took them to the top of their fields:

Marissa Mayer, CEO at Yahoo Long before her Silicon Valley days, Marissa Mayer worked as a grocery store clerk. But even then, she was known for fast results. To work in the express lane, she had to scan 40 items a minute.

Indra Nooyi, chairman and CEO at PepsiCo Showing early on that she could take on tough challenges, Indra Nooyi paid her own way through college. When she came to the U.S. to attend graduate school at Yale University, she took a job as a receptionist in her dorm. She worked the late-night shift — from midnight to 5 a.m.— because it paid 50 cents more per hour.

Tina Fey, writer/producer/actress Living in Chicago in the mid-'90s, Tina Fey worked as the child-care registrar at a YMCA before famed improv troupe Second City invited her to join. In 1997, she sent scripts to "Saturday Night Live" producer Lorne Michaels, who then hired her as a writer.

This week, I challenge you to look back on how far you've come in your career and identify the top two things that have helped you get where you are. From this, you'll see how you've been bold and all of the unique things you've already done. And, I hope, you'll be inspired to do more.