Many good points here. Yes, you must learn to deal with politics, but it's a skill that can be learned (and not particularly difficult, compared to some other interpersonal skills). You must also apply your talents in an effective direction (more on that below). And you must be careful not to become a prisoner of your own - or others' - expectations.
Beyond these, there are a couple of key issues: developing an effective strategy, and then learning to grind things out day after day. You will have ups and downs, but consistency is essential to success.
Strategy means finding a path that builds on little successes in a non-linear way. For instance, if you can swing it, it's better to go to school and then work, you'll make a lot more overall. So putting things in the right sequence - prioritizing - both on a day-to-day and longer-term basis, is a key skill.
Think through where you are really trying to go and ask, how can you get there most effectively? If you have to work a dinky job to stay in college, who cares, it's only for a while. In the same way, if you can't find the ideal job, take something else and keep looking. Each step along the way you'll be in a stronger position.
Once you settle on a basic strategy (no plans are ever carved in stone), you still have to execute. This is where it gets confusing for young adults. When you were a kid, you could sense progress almost every day, certainly every few months. It was like swimming across a kiddie pool. College was more like grueling laps in an Olympic pool, but you could still tell you were getting somewhere.
The adult world, however, is more like swimming in the ocean. You can't always sense progress, and sometimes waves come and push you back, or even under. And there are strong currents that you really do need a strategy to counter. So you need to keep focused on your long-term strategy, but break it down into medium-term goals. This medium-term goal-setting area is the most tricky and where many fall short. What skill should you learn next? Which area of your life should you shore up (make stronger) next - better car/job/housing/etc?
In grinding it out day to day executing your strategy, bear in mind you are looking to constantly move toward greater advantage, and distinguish leading and trailing indicators. Money is very much a trailing indicator, and it can be a huge mistake to focus on that. Focus on improving yourself and your relationships, figuring out where you can make your best contribution, and gradually handing the rest off to others.