Humility is something everyone has to re-learn time and again. Successful entrepreneurs, particularly young ones, typically learn this lesson, after they go through a period of overweening pride and hubris.

That's the case with Mehdi Maghsoodnia, who's left the startup world - for now - to be Executive in Residence at Trinity Ventures. Prior to his role at the Silicon Valley venture firm, Maghsoodnia was vice president of online operations at CafePress, where he helped grow the online business to $130 million from $30 million in four years.

In this segment of Lessons for Entrepreneurs, Maghsoodnia shared his three pieces of advice to entrepreneurs, based on his experience. 

When Maghsoodnia graduated from Stanford, he founded a company and sold it at a tender age of 24. Quite a success for the young lad. As one can imagine, at the time, Maghsoodnia was high on his horse and thought he knew everything. (Boy, do I know a few of those today). While Maghsoodnia didn't get into the details of those early days in his career, it was clear he realized that what he didn't know was that he actually didn't know anything. To borrow from Greek philosopher Socrates, "The only true wisdom is in knowing you know nothing."  To this end, his advice: Be humble and learn from others.

Secondly, Maghsoodnia says to value and respect the people you work with. "Really understand the quality of the peopley you bring to the entreprise and how you respect them."

Thirdly, focus on execution. "I learned that by mistake," he said. "You get excited and you tend to do so many things." 

Entrepreneurs need to be disciplined to say "no." Maghsoodnia shared his experience at his startup when he just graduated Stanford. The bottom line, he was trying to satisfy too many customers. In the end, he realized that he couldn't dominate a sector, geography or customer base. 

So, focus, be humble and respect your staff.