Skills are something we build through practice. If we're learning a skill, we don't begin with the impossible; instead, we build up to it through lots and lots and lots of iterations of simple, easy tasks: fundamentals.
For example, we don't ask first-time basketball players to shoot 3-pointers, or dunk it from the free-throw line. We show them the basic form of the shot; then, the beginner takes shots again and again and again.
When they miss again and again and again, we don't judge them for it; we know it's natural for beginners to miss! When we learn a language, we will "miss" again and again and again. It will take many, many tries before things get fluid and easy.
To carry the metaphor further, its key that we build language fundamentals in real communicative contexts, through trial and error, and mistake after mistake. Sitting in the classroom or in our rooms with a textbook, memorizing vocabulary and grammar structures, will not provide this experience.
Let's look at a metaphor for skill-building.
Imagine this scenario: There are two basketball teams. One that takes to the court each and every day to shoot shots, pass the ball around, and play scrimmages. A second takes to the classroom and hits the books. They study all the basketball theory; they memorize what each position in basketball does; they memorizing plays, and can diagram them all:
After one year of "learning basketball," the two teams play a game. Which team will win? Which team actually developed the skills required?
This is why classroom language learners are so often at a loss when they are confronted with real language, as used by native speakers, whether spoken or written, in real contexts. They have tricked themselves into thinking their study has some value without practice—without missing shot after shot, until actually beginning to sink them—without making language mistakes again and again, until the proper forms begin to sink in.
All the study in the world can't replicate the power of using language to communicate, of making mistakes, and building communicative competence: the fundamentals of language.