When you wake up during dreams, you'll remember it more vividly. And since dreams are wild and crazy to begin with, whatever you remember will be very vivid. What this may mean in your case is that you stopped breathing, since your muscles relax the most while in REM sleep. This is why you feel more tired and can't get restful sleep"”you're not able to sustain, deep, quality sleep. If this problem continues, see a sleep doctor.