Most people celebrate their 21st birthday by going completely wild — playing loud, rebellious music, hopping from bar to bar and drinking a ridiculous amount of beer.

But Bowling for Soup has already spent the last two decades perfecting those skills. So in preparation for its Finally Legal Tour — celebrating the band’s 21st anniversary — lead singer Jaret Reddick is fulfilling his daddy duties before getting ready to rock out at San Francisco’s Bottom of the Hill on Friday.

“I was out with my daughter the other day… (and people kept stopping me) to take a picture,” Reddick said. “And my daughter goes, ‘Isn’t it funny how, like, people used to wanna take your picture all the time, and then there was a whole time when no one really cared? And, like, now everyone wants to take your picture again?’ I just started laughing because she pretty much just described Bowling for Soup’s career. “

Reddick’s daughter — who was born on the day the band was nominated for a Grammy in 2003 — was exactly right. The band has had a unique career timeline, spurring them to develop a fanbase that spans multiple generations. Starting out in the mid-90s as a bar band out of northern Texas, it rose to mainstream fame nearly a decade later, when a censored version of its single, “1985,” made it big on pop radio and Radio Disney.

“it’s been an ever-evolving fanbase for us,” Reddick said. “It was real interesting to sort of find a balance of our bar-band vibe and comedy and wit, and to also be able to push the limits but not go crazy in front of freakin’ nine-year-old kids.”

But Reddick says in recent years, the band’s fanbase has “leveled out,” because many of its previously premature fans are now reaching their early 20s.

“When all of you guys were listening to Radio Disney it was crazy,” Reddick said of the group’s now college-aged fans. “Then y’all went to junior high and found screamo. And then now, you’re in college and we’re cool again,” he laughed.

Often credited alongside bands such as blink-182 and Green Day as benchmark artists in the early pop-punk movement, Bowling for Soup has played an enormous role in establishing the genre as it exists today. Last summer, the band celebrated its 20th anniversary by returning to the Vans Warped Tour, and the members were surprised to be touring alongside many acts who had grown up listening to their music.

“We were so well received by all those bands who were like, ‘We grew up listening to your album!’” Reddick recalled. “I said to my agent, ‘Isn’t this crazy?’ and he said, ‘Not really, if you think about it. If you look out there and you see who’s watching you play right now, yours is the first album that they bought as kids that said ‘shit’ on every song.’”

And while Reddick still takes pride in belting out Bowling for Soup’s classic tongue-in-cheek lyrics such as, “I almost got drunk at school at 14 / Where I almost made out with the homecoming queen,” fatherhood has helped his career veer toward a more family-friendly zone.

After the band provided the theme song for Disney Channel’s animated series “Phineas and Ferb,” Reddick became a recurring character on the show, providing the voice for the lead singer of fictional band, Love Händel. He also took over as the voice of Chuck E. Cheese after the character’s redesign in 2012.

Reddick mentions that because of his voice acting work on youth-oriented platforms, he often gets recognized in public purely because of his speaking voice.

“I was in line at Starbucks in the airport and I just started talking,” Reddick said. “And this kid — probably seven years old — he just turned around and literally looked me right in the eye and said, ‘You’re Phineas and Ferb!’”

As the band’s fanbase grows even further — both in size and in age range — Bowling for Soup is helping to expand the reach of pop-punk as a whole, thus revitalizing the genre that it helped make iconic.

“Pop punk has definitely not died,” Reddick said proudly. “In fact, it’s back with a fury.”

For those of us who grew up with the band and are now on the cusp of adulthood, listening to Bowling for Soup’s music fills us with a pang of nostalgia, similar to the feeling of recalling heartfelt, childhood conversations with our fathers — or quirky uncles.

But Reddick doesn’t see his maturing audience as a reason to feel as if he has an empty nest. In fact, he knows that Bowling for Soup already has a huge influence on even its youngest followers.

“There’s definitely a whole new age of kid that knows me from (my voice acting work),” he said. “But what’s cool is that those are the same kids that can already get on YouTube and they’re like, singing ‘My Wena’ to their parents.”

Bowling for Soup is playing at Bottom of the Hill on Friday.