CITY OF INDUSTRY, Calif. » We’ve known Michelle Wie half her life, since she was an intrepid 10-year-old golfer boldly and blithely going where no one had gone before.

Tomorrow she tees off in the second annual Kia Classic at Industry Hills Golf Club, the LPGA’s first domestic full-field event of 2011. She is finally old enough to buy a beer and celebrated her 21st birthday last October with friends at the Stanford-USC football game.

The girl who is “like forever 16 in people’s minds” plans to graduate from Stanford next March — less than five years after leaving Punahou, despite doubling as a pro golfer during her extended “summer vacation.”

“I have no idea what my GPA is now,” she said yesterday, a few days after finishing finals. “It’s still above 3.0. I’m keeping my head above water. It used to be so good my freshman year and then a steady decline.”

Wie has taken 20 units each winter to try and “lighten” her fall load — to 16 or so. Her major is communications and her final two semesters will be filled with writing and “social research.” Last semester, her studies involved American Government — “because I felt like I didn’t know much” — and journalism.

Now it is time to pack up puppy Lola and go back on tour. Her other life is what brought her fame and immense fortune. Stanford has brought her balance.

Or is it the other way around?

“When I’m stressed after golf I have school,” Wie says. “If I’m stressed out from finals or papers I really enjoy being on the golf course. They feed off each other, which is really nice.”

None of her Stanford buddies swing a golf club, at least not well. “A couple of friends took beginning golf,” she shrugs, then elaborates. “They’re going to be in banking and realize they need it.”

Here are some numbers for them to ponder. If Wie finishes first this week, or second or third, she will surpass $2 million in official earnings since getting her card before last season. She has made much, much more from endorsements with companies such as Nike, McDonald’s and Kia.

The part-time golfer is ranked 11th in the world and has two wins and 14 top-10 finishes the past two-plus seasons, including a sixth in this event a year ago.

She had 13 more top 10s as a teenager, before she was Facebooking, tweeting (themichellewie), blogging (ablackflamingo) and becoming an LPGA member. She describes ablackflamingo as “A mindless blog about life … and the stuff that doesn’t quite fit in.”

Somehow she has made it all fit. After spending half her life under a relentless microscope, Wie has found a comfortable place for that prodigious talent and all the other stuff “that doesn’t quite fit in.”

Without that stuff, the golf would not work.

“You can’t have too much knowledge,” Wie says. “Good players play 30 years. Golf is always changing. You can’t ever stop learning. But I’ve definitely learned a lot the last few years. I definitely grew up a lot. I appreciate the downs and ups. I’ve learned from everything — how to handle situations, how sometimes they are not fair.

“I think that’s really the hardest thing to learn is trying not to care so much. Just have fun out there. When you have some bad days you have to be over it. You have to be like, ‘This is fun and I’m absolutely privileged.’ It’s a really fun learning experience.”

She is not 10 anymore. She is all of 21.