You. Sit down and pay attention. Yes, you.

Drop that lollipop, wipe that stupid grin off your face, and for heaven’s sake, turn your pants around the right way.

I’m not saying this to scare you, but you’ve already been in first grade for a couple of days, and I don’t like what I’ve seen.

You’re not in kindergarten anymore, kid. These are the most important 10 months of your life, and you’d better take them seriously.

Last year was all one big party. A playdate with 20 of your best friends. You sang songs, painted pictures, frolicked on the playground, ate cupcakes. If, by the end of June, you were able to latch the Velcro on your shoes all by yourself, the year was deemed a complete success.

Now, however, school is for real. It all counts. You will be expected to learn stuff, important stuff, such as math, science and grammar. Two plus two better equal four, or else.

Your report card will have no more “S” grades for super-duper. No “D” for delightful, no “F” for fantabulous. From now on, a D on your report card is for dubious future. F is for failure. It all goes on your permanent record.

Get a D on your report card in the first semester of first grade and you automatically get rejection letters from Harvard, Yale and the rest of the Ivy League, along with Stanford and MIT.

College admissions become more competitive every year, and scholarships become increasingly scarce. Can your mommy and daddy afford to give you a few hundred thousand dollars for your schooling? Maybe you’d better ask.

Your parents aren’t the only ones banking on your success either. Unlike your kindergarten teacher, your new teacher isn’t just a sweet woman who loves children: She is someone with aspirations. She wants to move up to fourth grade, and ultimately 10th grade French. She will be judged on how you perform. Comprende?

It’s important that you realize this is serious business. You can’t coast on your youthful charm and playful hijinks anymore. In fact, playful hijinks are a big negative.

Your little behavioral escapades — writing “I like poo” on your desk in finger paint — will no longer be considered adorable. It will be a black mark on your record. You’ll be sent to a child psychologist for observation and diagnosis.

I know this is all new to you, and it’s not easy. Every student faces an adjustment period when he or she finishes school and enters the workforce. The adjustment from kindergarten to first grade is even more difficult.

You cannot just go to the bathroom whenever you want; you have to hold it until a teacher says it’s OK. You have to know ALL of the letters of the alphabet; 21 or 22 just won’t do. You can’t just break into song whenever you want, and spinning around in a circle until you throw up is seriously frowned upon.

There are no more “happy breaks.” There are no “Barney” videos just to keep you quiet. All classroom movies from now on will be documentaries on the Enlightenment, personal hygiene and/or the atom bomb.

It is time to grow up and work hard. Read books. Do your homework before playing video games.

You will be classified soon. Do well and you will be put in the advanced second-grade class next year, then fast-tracked into third grade. You will be put into advanced classes and ride the express to success.

Perform poorly and you will be shuffled into a giant classroom where you will be herded toward graduation and a life in manual labor.

Good grades, of course, aren’t your only task. Make sure to sign up for lots of extracurricular activities. It’s never too early to start building an eye-opening resume. Join a club, play for a team, run for some kind of student office, even one like class secretary that doesn’t have any power.

If you lose the election, nag your teacher until she creates a special post just for you. Hamster historian or beanbag regulator are better than nothing, and when your verbal skills are better, you can embellish them anyway.

Hey, embellish is a good word. Learn it.

First grade is the foundation for the 11 years of schooling that follow. If the foundation is already crumbling in year one, the whole thing will topple before puberty. Be concerned. Be very concerned.

Email Steve Ouellette: ouellette1918@gmail.com