From your description it seems like it is difficult to wake you up once you are asleep. As long as you do not have any symptoms like excessive daytime sleepiness, I would not worry about it. We often do not remember our dreams and many feel as though we do not get any dreams. During some parts of the night it is difficult to be awaken by a person. It is possible that your family/friends might have tried to wake you up in one of those phases of sleep during which it is difficult to awaken a person. Please see a sleep specialist if you do have excessive sleepiness during the day and or feel restless despite sleeping soundly for at least 8-9 hours.