vocabulary..the hardest thing for so many people...

When I talked with some teachers about english learning, they told me that it only takes about 6 months to fully learn english enough to take have a fluent conversation and can write and read fluently. But learning vocabulary is really necesary and it can takes a lot of time depending of on the interaction of betweeneach person with and other people of influences, such as tv, music or reading.
I've studied a little english and I'm enough capable enough to write this, but I know that I need to learn so much vocabulary to join with people out in the real world.

what do you think about this? (please, correct me if it is necessary)