To dream that you are using marijuana implies that you are trying to escape reality. Perhaps you are trying to numb some emotional or psychological pain. If someone else is using marijuana or trying to get your to use it, then it indicates a negative influence in your life. You are on the verge of losing control. Perhaps you feel that your identity and sense of self is being compromised or disrespected. The dream may also be a reflection of waking drug use.
To see or smell marijuana in your dream suggests that you are experiencing an expanded sense of awareness and consciousness. You need to take advantage and draw insight from this new consciousness. The dream may also mean that you need to look on your inner strength for stimulation instead of relying on outside forces.