now.

...Now. I never remember my dreams, does this mean that I am so deep in my sleep that I can't achieve a level of conciousness ( I mean I"m unconcious) to remember them?

That's even better in a way. You got a deep profound sleep, what more our mind needs to function properly?

Actually it is all a matter of how much importance you put on the subject. Many people don't give much thought to what they do while asleep. As a result they just go to sleep and wake up with almost nothing in the middle. The more importance you put on it the more it will happen.

You can try several things:
You can wake up a little earlier than usual, to catch yourself off guard and have a better chance at remembering-
You can try to blank out your mind before you go to sleep, and concentrate on remembering the dream when you awaken-
You can, when you wake up, write down anything that seems relevant to your sleeping hours, even if they are fragments of the dream (the rest may suddenly, sporadically come up later while you are daydreaming)-
And you can try not to get up right away when you wake up- just lay there for a little and see if this helps your memory at all.

While I am no professional, this is the advice my own book tells me.

No, I bet you are having dreams and just not remembering them.

In addition to the advice others have given you, you may want to try vitamins. When I don't take a multivitamin for several days and am not eating properly, my dream recall goes down. This could be due to lack of vitamin B6, which some people say is helpful for dream vividness and recall.

Also, I find that when I ignore my circadian rhythms, I have dream recall issues. If I have to get up before 7am (barring intentional wake-back-to-bed lucid dream techniques), I can't remember my dreams well. It doesn't matter how early I go to bed, or how many hours of sleep I get. That's just how my body works. Once I adjusted my schedule to allow me to sleep in later (I'm lucky to have a flexible workplace), those problems diminished.

Also, someone else could probably tell you about timing your waking time so that it co-incides with the end of a REM cycle. I've forgotten the details :)

As Mithril Dragoness, suggests, definitely write down ANYTHING you recall, even if it's only a fragment. This gets your subconscious to accept that dreams, even small ones, are important enough to bother with.

Good luck! Lots of people have been in your shoes and have overcome this, so you have hope.