Yes, the words I hear a lot in dramas are definitely the easiest to learn! The words I don't hear as much really don't stick in my mind so well, though. I probably made it sound like I know a lot more than I do, I'm sorry! But the holes in my vocabulary mean that I can only understand basic conversations that don't include lots of unfamiliar words. So sometimes I can understand quite a lot and other times I'm totally lost...it just depends lol.
I did want to mention that the course I'm taking is very good and it's free online. Whether you're interested in learning some basics or becoming fluent, it's an amazing tool. If you want to check it out, here is the link: How To Study Korean.