How do you learn Latin?

I see that it's very hard to find out how to learn Latin, but I have heard of people that know it already.

I studied it for 4 years in high school. Both universities I attended offered courses and majors as well. In fact, many high schools and colleges offer courses in Latin, probably most... at least in the US. Check to see what courses you can find near you.

I know nothing about them, but you could also check out:
http://www.learnlatinonlinefree.com/

Not technically. I mean, I'm about to go into high school and I'm already learning Latin. The only thing that might be difficult is conjugating verbs and the nominatives and accusatives of Latin. But, a good way to learn is go to a online Latin Textbook and subscribe and Learn it up!