Happy birthday, America!

We have a big party planned for you, with fireworks and barbecues and bands playing and lots of fun for your special day.

You are 235 years young. Compared with other countries such as England and China and France and Russia, you are but a strapping lad. Those guys are practically ancient civilizations.

But the truth is, you are no longer a new nation. You are not the child-state you once were. As you have grown into a mature country, we have been filled with a parent’s pride. There are, however, duties and obligations that come with that maturity.

America, it is time to put away the playthings of your childhood, time to reconsider the follies of your youth. You must start acting your age. I am sure you don’t want to hear another lecture (Young man, I’m talking to you!), but think of this as your graduation commencement address. I hope you begin thinking about your place in the world and what you might to grow into after your birthday bash.

Let’s start with:

Infatuation with “ism”s: Every few decades, you manage to get yourself entangled with some philosophy from the wrong side of the tracks. These torrid affairs always end badly.

Every adolescent goes through this phase. You see a pretty ideology from across the room. She bats her big, blue eyes at you, and you fall head over heels. As any more experienced country will tell you, these infatuations are merely a passing fancy. They are not the makings of solid, long-lasting philosophies.

Your parents made sure you had a good upbringing and a Constitution that sets up some fine parameters for you to live by. How about avoiding the passionate flings with these isms and instead work toward being more pragmatic, more practical, even more technocratic?

Infrastructure: As a younger nation, you could party all over the world, intervening in other nations’ affairs, and still make it to work on time the next day. But you’ve really allowed yourself to go to pot.

You need to start taking better care of yourself. Your interstate highway system was once the envy of the world. You crisscrossed the nation with railroad tracks well over a century ago. Your bridges and tunnels were second to none, and your naval ports handled more tonnage than any three nations combined. You discovered electricity, invented the light bulb, strung electrical wires coast to coast. You invented air travel and opened airports in every major city.

Now look at you: Your roads are pitted, your bridges are falling down and your airports look like they belong in a third-world nation. You call that a naval port? Not only do they look like junkyards, they are still a gaping security concern. And don’t get me started on your electrical grid! It is creaky, inefficient and vulnerable to cyberattack.

While you were getting flabby, the rest of the world was hitting the gym. Most of Europe and nearly all of Asia are in much better condition. Even emerging nations such as India and Singapore have better airports, wireless telecom and broadband Internet.

You’d best start taking better care of your infrastructure — it’s the only one you have.

Magical thinking: When will you learn there is no free lunch? Anytime some fast-talking salesman comes around promising you something for nothing, you fall for the same old scam.

Wise up! You cannot buy every nonsensical infomercial sales pitch for every foolish gadget dreamed up by these hucksters!

You must recognize that:

•You cannot take over a country with a handful of under-equipped soldiers.

•Tax cuts do not pay for themselves.

•There is no such thing as a “temporary” entitlement program.

These are just the most recent false promises made by those city slickers. We know that a sucker is born every minute, but must it be you all the time?

Health: Don’t look now, but your citizens are in even worse shape than your infrastructure. Your people are a nation of obese, sedentary, TV-addicted, junk-food loving, pill-popping couch potatoes.

I know you are a free country and you cannot simply order everyone to hit the gym and skip dessert. But you have made tremendous progress in getting Americans to stop smoking and to wear seat belts. The economic benefits of those two issues alone have been enormous.

Unless you do something about it, the health costs of your citizenry are going to bankrupt you. I have every confidence that if you seriously put your mind to this issue, you will come up with a creative solution.

Loyal opposition: Not everyone in the world (or even in the country) is going to agree with all you say and do. And you know what? That’s okay. Debate is how we reach an intelligent conclusion, how a working consensus is formed.

You unfortunately have this tendency to see the world in black and white. There are nuances and shades of gray. Just because someone disagrees with you does not make them disloyal or a traitor or a bad ally.

And your politicians must remember that every fight does not require a scorched-earth response. Learn from President Ronald Reagan. The Gipper and Tip O’Neill fought famously over all manner of legislation but could always share a beer together after the debate.

Learn to gracefully accept opposing viewpoints and loyal political opposition. It is a sign of maturity.

Money in politics: Over the past 40 years, you have allowed the inflow of special-interest dollars to overwhelm and corrupt the political process. Congress is now a wholly owned subsidiary of Wall Street. The bank bailouts benefited bondholders but not the financial system. There is no reason why your taxpayers should subsidize Wall Street speculators. With Congress in the grip of these special interests, it is impossible to even contemplate reforming the tax code or the regulatory system, much less have an intelligent discussion about a national energy policy.

What happened to your roots as a one-person, one-vote democracy?

The solution might be a constitutional amendment to provide for public funding of federal elections and to restrict, or at least require full transparency about, the special-interest lobbying that has perverted the legislative process.

Government as the problem? “Government” is not the problem, “bad government” is the problem. There is an enormous distinction between the two.

Being surrounded by two oceans — and being so powerful since WWII — has allowed you to become too insular. Your “not-invented-here” attitude has led you to miss many other good ideas. Have a look around the world and see what other countries are doing right:

Canada managed to come through the financial crisis unscathed — what was it about its banking regulations that protected it? Why is Finland the best country for education? Why does Australia have the world’s lowest jobless rate? How are Germany’s highways so darned good? What is it about Japan’s health-care system that has made it the best in the world? Norway has the highest adult literacy level and is often ranked as having the best quality of life; what is it doing right? And Singapore has the highest per-capita GDP and one of the recession’s fastest-growing economies. Why?

It sure wouldn’t hurt you to put your pride aside and take a few lessons from the best ideas in the world.

America, you are 235 years old, and you should be proud of all you have accomplished. You are still the most powerful country on Earth, but if you are not careful, China or the E.U. is going to pass you by.

Enjoy your birthday, but starting tomorrow, you have a lot of work to do. America, it’s time to grow up.

Ritholtz is chief executive of FusionIQ, a quantitative research firm. He runs a finance blog, The Big Picture.