I took the course two years ago as well. This time I had specific purpose for taking the course. I wanted to stop my mind from wandering and thinking.
My mind was thinking on auto-pilot. I figured that out while reading "The Power of Now".
While I took this course two years ago, I thought I found something I was searching for, and that I'd never be unhappy again because I had learned to be happy. I had learned to control my emotions through meditation.
But never did I thought it will fade away eventually. And when I completed the same course for the second time, I learned lots of things:
Everything you learn will eventually fade away: Nothing lasts forever, and even the knowledge and idea fades away. You need to practice it daily to keep it fresh in your mind. If you don't meditate, you won't be able to concentrate better. You can go from enlightened, to low state of mind in a matter of weeks, or even days. You can't always have the same state of mind. You can, but you'll have to work for it.
You have to work hard for attaining your goal: Success won't come to your naturally without any effort from your side. You have to put in huge amount of time and effort to get some returns from the mediation or anything else you're doing.
Peace comes from hardships: The course is difficult. You'll felt like quitting in the initial stage. Your whole body pains. However, if you last that, you'll find inner peace. If you just concentrate on easy things, you'll only get mediocre results.
Simplicity is the ultimate sophistication: While you achieve your end goal, you'll find that it's simple, instead of being complicated. Generally, we think achieveing success is a complicated task.
The more you dwell on complication, the more complicated it gets: There is a quote, "The harder they come, the harder they fall." This is true in case of making our lives complicated. If you keep dwelling on it, you get stuck in it. To get out, you need to stop dwelling on complicated things.