BERKELEY, Calif. - A passion can drive you to do unexpected things.

Going back to college at age 47 is a daunting task in its own right. Joining the university's marching band - full of fresh-faced students in their late teens and early 20s - is another challenge all together.

Cynthia Erb of Alamo, Calif., is taking on both challenges to realize a pair of personal dreams.

The 47-year-old retired investment banker has a lot of family ties to the University of California, Berkeley, but earned her own bachelor's degree elsewhere more than 20 years ago.

Following her retirement, she decided to indulge her long-term interest in design, taking classes at Diablo Valley College before applying to Cal as an architecture student.

But before she was even accepted to the program, Erb started thinking about trying out for the Cal Marching Band after watching the band perform when she attended football games. Previously a clarinet player in her high school marching band, Erb decided it was time to brush up her music skills with the hope she would soon be wearing a band uniform.

"It's like riding a bike - you can always play," Erb said.

Her husband, Gordon Erb, may be encouraging and supportive of his wife's choice, but the first thing that went through his head when she mentioned joining the band was, "Oh my God, not that," he laughed.

He knew school and band practice would take up an immense amount of time. The Erbs have one son, Mikey, 16, who lives at home. Their other children, Andrea, 24, and David, 22, live in other parts of the state.

Robert Calonico, director of bands, said older students - often in graduate school - occasionally try out for the marching band. He didn't know for sure if Erb was the oldest student ever in the band, but the oldest in recent memory were in their late 30s or early 40s.

During the band practice on Maxwell Field on the north side of Memorial Stadium, Erb looks like any other college student. Wearing athletic shorts, a "California Berkeley" T-shirt - her closet is full of them - and sunglasses with her hair pulled back, Erb marches to and fro with the best of them.

"I don't ever get tired," said Erb, who has run marathons and competed in tennis as an adult.

Although she comes home every night to her husband and son, Erb still likes getting the full experience of being a student. She enjoys sipping a morning latte while hanging out on campus, which she said is more scenic than she expected.

But she's careful to mention that while she may be a regular student, she considers herself an "adult in the mix."

"I'm not trying to be a younger person," Erb said. "I don't try to do all the things that they do."

Cynthia Erb described the experience of being in the tunnel on game days, waiting to enter the stadium packed with 70,000 people - her heart pounding. Going out from the tunnel and into the light of the stadium was one of the things she most looked forward to when joining the band.

"I just look around and I think, 'Wow, my father played here, my grandfather played here,"' Erb said. "It makes me really proud to be a part of it."