Joe Schumacher, CEO of King of Prussia’s Goddard School, is one of several successful entrepreneurs who have recently offered their advice to people starting their first job, writes Geoffrey James for Inc.com.

Schumacher started working when he was just twelve years old as a Warehouse janitor. He said that there were two things he wished he had known at the time.

The first thing that quickly became apparent to then young Schumacher was that people can get very invested in their own way of doing things.

This can make it hard for them to realize that their methods have either become completely outdated or could be significantly improved with some minor changes.

Soon after he realized that for change to be successful, both patience and good diplomacy skills are essential for any adjustments to be considered, let alone accepted.

“Had I known these two things then,” said Schumacher, “I might not have been unceremoniously fired after just a few weeks.”

Natasha Case, CEO and Founder of Coolhaus who started as an Architect at Disney, also noted that “Your beginning work experiences are not only about the skills you will learn, but are very much about the foundation of your community and professional relationships.“

Read more sage advice from other successful entrepreneurs at Inc.com by clicking here.