Politics at work

Hi All,
Had my appraisals done last week. As usual were on expected lines and got jacked royally. Politics is one thing which i have never been able to manage. The way people manipulate the system, their bosses is beyond my comprehension. I know i need to learn how to manage the system to survive in the corporate world. But i have philosophy which says that let your work speak for yourself, slow and steady wins the race. How true it is the present context is what i need to understand and evaluate.
I worked hard for the entire year with my colleague on a number of reports but at the end of it what i came to know was that he has taken credit for my quota of work. Whose fault it was? His or mine. I would say mine cuz i let him take credit for it. This was my major learning for the year. Dont let someone else credit for whatever work ya do. No matter how much you have to fight for it, you need to stand up for yourself.
Life is not fair and wont be fair. I know my capabilities, my strengths and my weaknesses. I just need to learn how to project it in front of other people and not rely on other people for any help. I trusted people at a higher level who i thought knew and observed the work i was doing but it was sad that they were biased and hypocritical in their judgement.
I have bounced back from a lot of setbacks and am sure will conquer this one and come stronger and better.
Amen and stay in touch