"If you're in college taking a course in economics, or if you hold a steady job and are just barely getting into the world of investing, or if you're just plain curious about the world around you, today is a great day to learn a lot about the stock market," Jim Cramer told his "RealMoney" radio show listeners Friday. That's because after six lean years, Wall Street is excited again as stocks representing "every nook and cranny of the economy" post a broad-based rally. It's not just tech or medical, Cramer said, and many of these companies are reaching all-time highs -- or highs not seen in six years. "This rally has breadth," he added. It seems counterintuitive, he said, given the fact that there's bad news everywhere. "The Iraq war ... and problems in the Middle East dominate the news," he said. "The deficit is out of control ... the government has no fiscal discipline. Foreclosures are up, home equity loans are down. Inflation is higher ... and the U.S. government just raised the debt level to pay the bills." But he believes that three reasons justify the exuberance: First, there have been more mergers and acquisitions "than I have seen perhaps ever," Cramer said, pointing to McClatchy ( MNI) buying Knight Ridder ( KRI), AT&T ( T) buying BellSouth and Capital One ( COF) buying North Fork Bank ( NFB) as examples. Close to $150 billion was booked in deals in just the last 10 days, he said. This shows that even though the stock market junkies, the people who determine prices daily, don't have a lot of enthusiasm for stocks, the companies themselves see real value in the market. "Take your cues from the players, not from the talking head portfolio managers on TV and in the papers," he said. Plus, real estate is done, he said, citing a report from the Federal Reserve that said the sector is slowing. Money from real estate is going back into stocks.