i always notice that if i smoke and then go to sleep, i don't feel as rested in the morning as when i go to sleep sober. it's become obvious to me because i can go to bed at 3 AM and feel less tired waking up at 6 AM if i'm sober, but if i went to bed at 10PM adn woke up at 6 AM after being high the night before, i'll feel more tired.