The young people who started the Occupy Wall Street protest a few weeks ago are about to learn some important lessons about life in the grown-up world.

Lesson One: If you don’t have an objective, someone else will be glad to give you one. In this case the “someone else” means both labor unions, which have been fighting a losing battle to mobilize popular support, and the Democratic Party, which is searching for ways to feed public antagonism toward the financial industry without reducing the value of anybody.

Lesson Two: Protesting against something is useful if you want to prevent change. If you don’t want Wal-Mart coming to your town, you protest against Wal-Mart. But if you actually want change, you have to be for something. Until the union activists moved in, Occupy Wall Street was not for any particular thing that I could determine. It was just against Wall Street, whatever that means.

Lesson Three: You don’t drive a car from the outside. You need to have your hands on the controls. This, incidentally, requires you to learn how to drive. People marched for civil rights, which was good and important, but the civil rights movement ultimately progressed because Congress changed laws, lawyers brought lawsuits and judges made judgments. If you want to make an individual impact, rather than just be part of the crowd, you have to acquire skills that put you in the driver’s seat. Most protest gatherings, like the anti-austerity protests ongoing in Greece, simply vent public frustration without ultimately changing anything. Change requires an achievable goal and the know-how to achieve it.

Even in the current post-bubble era for U.S. real estate, young people in New York City have much to complain about when it comes to housing prices. They seldom make the connection between the absurdly tight rental market, which makes New York one of the few places where renters customarily pay commissions to brokers, and the price controls on rents that have been in effect since the city declared a housing emergency in 1947.

Many of these young people are saddled with debt left over from college, and they are struggling in a stagnant economy and stalled job market. It is probably safe to say that many were Obama supporters in 2008 and that most will still favor him next year – if they are motivated enough to vote at all. And I suspect a lot have a history of “progressive” sympathies, such as advocating for living wage laws back on their college campuses. I apologize for the generalizations, but there is, as yet, no “Occupy Wall Street” platform that I can quote.

But outsiders will be happy to provide one soon enough. Unions have taken a drubbing in elections and state legislatures all over the country, and they are happy to make common cause with the protesters. Unlike unemployed twenty something, however, the unions know exactly what they want: card-check organizing rules, collective bargaining rights for public servants, pension and health benefits that don’t exist in the private sector, and higher taxes – which most of the Occupy Wall Street protesters will someday pay – to cover the bill.

 If some of those Wall Street firms being protested set up a table and held a job fair across the street from the protests, would they draw a crowd? It’s an interesting mental image.

Such events always pose the risk that fringe elements, such as the clowns who rioted in Seattle during a 1999 meeting of the World Trade Organization, will subvert the protest to their own agenda. Police overreaction, the granddaddy of which was at the Democratic Convention in Chicago in 1968, is also a risk, but one which – in a mild way – protesters would welcome for its publicity value, as in last week’s arrests on the Brooklyn Bridge.

The more likely outcome, though, is that these protests will simply be co-opted by the existing power structure of the political left. Democrats are eager to find someone to run against in 2012 as they struggle with their party’s own record on the economy. The bogeymen of choice have thus far been the Tea Party, the elusive “millionaires and billionaires” and, intermittently, Occupy Wall Street. The party that produced the economy that left these young people frightened and unemployed will tap them to protest their own fear and unemployment.