There was only one place in Tucson last weekend where you could hear Bill Gates' father recall his son's defiant youth.

William Gates Sr. was one of more than 400 authors featured at the two-day Tucson Festival of Books, which wrapped up Sunday and drew crowds in the thousands.

People gathered under a tent Sunday on the University of Arizona Mall to hear Gates Sr. discuss his book, "Showing Up for Life: Thoughts on the Gifts of a Lifetime."

In it, Gates Sr. describes the lessons and values he has learned and shared with his three children.

His son, who co-founded Microsoft, didn't always respond to authority, Gates Sr. told the audience from a comfy leather chair.

"It wasn't easy because he's a very intelligent human being. He was comfortable with himself, and he didn't need his parents, and he made it clear he didn't need us," Gates Sr. said.

He and his late wife, Mary, took the younger Bill to counseling and were told they probably should change their parenting style, because Gates Jr. would win most conflicts with them.

Still, Gates Sr. and his wife found much to love about their son and his desire to learn.

"It isn't just curiosity. It's an absolute urge to find out and understand," he said.

Vail resident Kathie McClellan took in Saturday's festival and returned Sunday to hear Gates Sr.

"He was very open about things," she said.

McClellan also attended the inaugural festival and had just one problem with the event: There was a lot to pick from, and she couldn't see it all.

"There is so much to do, and it's so diverse," she said. "It's good for all ages."

Kaya Castle, 5, found plenty to do in the children's area with her mother, Nicole.

"We got to see a puppet show, and we got to get an umbrella," Kaya said.

She also went home with free books.

"I'm learning to read. I like books where I get to learn," she said.

The Founders of the festival couldn't say how many people attended the event, but they did say crowds surpassed last year's total of more than 50,000 attendees.

See more photos from the 2010 Tucson Festival of Books at azstarnet.com/gallery online.

Contact reporter Andrea Rivera at arivera@azstarnet.com or 807-8430.