This is critically important. In the past few months, I've done a lot of networking with the tech entrepreneurs in my city. After speaking to these guys, I became aware of problems I didn't even know existed. It turns out that corporate South Africa (and probably the world over) have a massive number of problems they need solved. For example: fleet management, business reports, operations (like using Voronoi diagrams to see which restaurant chain 'dominates' an area). This surprised me because as someone without exposure to a real business environment, I couldn't conceive why people would actually buy reports products and resource planning software. If you asked almost any CS major to explain what a 'enterprise resource planning application' should do I can quite safely bet that they won't be able to accurately describe what problems it addresses and how it solves them (assuming the grad has no first-hand experience in dealing with this kind of problem).
I realised how as an individual I have been exposed to mainly B2C companies. Now, having been introduced to real, profitable B2B companies, I see that the domain of problems to solve and businesses to build is huge. 'Get out of the building' really summarises this concept well. Get exposure to real business problems and you will find someone who has an unsolved problem that you can attack. A nice example of this (not a business problem but a real one nonetheless) is the other day I had to collect my calculus test. There were 1000+ people contending with each other to find their paper in 50 semi-sorted piles. It was chaotic. I know that there is a better way to do this (fast and efficient distribution of unique papers to 1000+ people) - I'm currently thinking about how to solve this problem. The takeaway idea here is that there are tons and tons of problems out there and exposure to the real world will give you the opportunity to see these problems and begin solving them.