Joshua Reeves bought a few thousand dollars worth of Berkshire Hathaway shares in 2004, with some money he made from an internship at Intel. He'd just finished his freshman year Stanford.

Thirteen years later, as CEO of a $1.1 billion software start-up called Gusto, Reeves took advantage of his Berkshire ownership and traveled to Omaha, Nebraska, for the company's annual shareholder meeting.

For Reeves, who's read a number of books about Warren Buffett, the event marked the end of a two-week, 12-city road trip visiting Gusto's small business customers. Gusto's software is designed to simplify back office functions like human resources and payroll. He took the cross-country trek in an RV, before flying to Omaha from Jacksonville, Florida, on Friday.

"Books are great, but nothing can replace some face-to-face interactions," Reeves said in an interview on Monday, before hopping on a flight back to San Francisco. "I sat there for seven hours writing pages and pages of notes."

Reeves spent Saturday at the CenturyLink Center in Downtown Omaha, listening to the entire presentation and question-and-answer session. On Friday, he strolled through the exhibit hall for what Berkshire calls "shareholder shopping day," viewing demos from Dairy Queen and See's Candies as well as jet engine maker Precision Castparts and homebuilder Clayton Homes.

Reeves said he listened intently both to Buffett's views on technology and tech companies as well as his broader advice on leadership and building businesses.