The toothbrush-hurling incident was not the first sign of troubled times, but it was the only one that left me with a bubblegum-flavored forearm and my daughter sobbing about academic impatience.

Why can't kindergarten start NOWWWWWWWW? Jane wailed. I'm ready! I've been ready.

That was Sunday. Today, her back-to-school dreams come true, not a moment too soon for both of us.

Some kids are terrified about going to kindergarten. Mine is cocksure. Some kids cry when plagued with doubt. Mine rolls her eyes.

It's all a show, of course. As a rule of thumb, if she's sucking hers, it's to keep the anxiety from escaping.

Jane may be a teenager in her mind, but in real life, she's just 5. She loves to read and do math, but still can't tie her shoes - a task she knows friends have mastered.

When her new teacher asked for a written introduction, it provided a rare opportunity to sum up my adorably eager, if complex, firstborn in a single sentence:

"Jane loves to learn but can be difficult to teach because she thinks she already knows everything."

Did any other parents write that? I don't know. It's all new to me, too.

Little girl's big adventure

So how did I spend the summer leading up to my little girl's big adventure?

In June, I got whupped in Monopoly by a junior Donald Trump. One night, Jane had so much money she generously bailed Mom out of jail.

But in July, a backward monkey-bars routine ended with my fearless playground performer landing painfully on her left wrist.

A hot-pink waterproof cast became a fashionable symbol of Jane's frailty. Neighbors lined up for arm autographs, but she kindly reserved me space near the thumb.

By August, the talk was all school, all the time.

Together, we sat in front of the computer toggling between Web sites in an epic search for the perfect backpack. Naturally, Jane opted for monogramming, the better to announce her arrival.

Though my daughter inherited an incurable sweet tooth, I have never seen her as excited about chocolate as she was about school supplies. The night we stormed Target, she pleaded with me to go "off the list."

My kindergartner craved a scientific calculator. She longed for a protractor, despite having no idea what it was or how to use it.

Why, I asked, do you need that?

Jane shrugged her shoulders and, for once, was at a loss for words. She pointed to a tan tween with braids who had just tossed a protractor in her cart. 'Nuff said.

Mind-blowing science

As September approached, Jane seemed to grow taller and more irrational by the day.

One minute, she'd be sweetly showing her little brother how to play the ukulele. Then she'd melt down because he touched her toy.

Our helper happily set the table without being asked, only to collapse in tears on a pile of laundry after a request to fold a few towels.

The irony of it all came in the form of the "Mind-Blowing Science Kit." Jane raved about how much fun it was to make volcanoes. This from a girl prone to her own random eruptions.

As we walked to kindergarten orientation last week, Jane skipped while I fretted.

Will she make friends and remember her manners? Will she learn humility before algebra? Will she work so hard at being "good" Jane at school that she unleashes "bad" Jane at home?

Yesterday, father and daughter swung by the office en route to a last hurrah at the zoo.

"Mommy's writing about you going to kindergarten," I told Jane. "Anything special you want to say?"

Strapped in her booster seat, my not-so-little girl wore a pink seersucker sundress, a red fanny pack, aqua Crocs, and a wide smile. She did not hesitate.

"Tell them I'm excited."

That makes two of us, kid.

Contact Monica Yant Kinney at 215-854-4670 or myant@phillynews.com. Read her recent work at http://go.philly.com/yantkinney.