I have studied game development in university  for 3 years.

I still feel very confused about how to develop a game.

Yes I do have made some project and get high score in class. But it is far from a game we may see and play every day. So i feel very diffident about what i'm going to do in future. I'm not sure how far i am from an "average" game developer. I feel i learned something so i have more knowledge than those who not studied, but there a much more thing i have no idea about. For example, I do know use some graphic engine like OpenGL, but i'm like an ancient people get a modern machine by chance and studied it for years to know how to open the switch.

Is that normal to all others who study game development? Feels what we learned in university is miles away from what we feels like?

26 minutes ago, Cold.bo said:

but i'm like an ancient people get a modern machine by chance and studied it for years to know how to open the switch.

That is what it feels like when you start. You read how to do X and how to do Y, like a parrot talking by just repeating words.

It takes a while but you do learn from every attempt. It takes a lot of practice but you get better each time.

34 minutes ago, Cold.bo said:

I feel i learned something so i have more knowledge than those who not studied, but there a much more thing i have no idea about.

There is no school that can teach you all about game development, you would be stuck in the school for your whole life.

You did the theory and it's now time for the practical, use what you have learned and make your game.

7 hours ago, Cold.bo said:

Is that normal to all others who study game development? Feels what we learned in university is miles away from what we feels like?

It's a sign that you're curious about the world, you want to know how it all works. Since obviously, the world is much larger than any single person can ever understand as you have started to realize, you start to feel a little lost.

This is perfectly normal, I had it much of my life. Knowing what you don't know yet guided me on my explorations into new areas.

Unlike common believe, university in general doesn't aim to teach you much practical knowledge. Instead, they teach you how to tackle a problem you have never seen before. They also teach you solid background theory that you need for that task.

The reason is that practical knowledge is easy to obtain (just do it for several years). A second reason is that such knowledge ages quickly, not in the last place because the discipline changes rapidly. I never learned OpenGL at University for the simple reason that it didn't exist yet. Same with distributed version control. I learned about Object-oriented techniques, but those ideas have changed a lot since.

However, since I know how to deal with an unknown area of knowledge, I can adapt, write basic OpenGL, use git, and understand what C++11 is doing and why (haven't started on C++14 and 17 yet, but they will arrive at my doorstep somewhen in the future too).

You shouldn't expect to finish your university course and simply be ready to walk into a job. The point of university isn't to teach you how to do that job, it's to teach you how to learn on your own. You should be making games in your own time, constantly, not because you need to for some particular class. 

From my expierience, Colleges and Universities teach you literally basic shit, you realize that when you start something, there are so many game engines nowadays, you need to invest some time(or even money) to learn how to work on them. But if you really into it than you will learn fast enough. Good Luck dude