I have found that God gives important dreams or visions concerning crucial turning points/decisions in our life (God gave Peter the important vision of creatures in the net at the turning point of the Church reaching out to the Gentiles).
In 1988 as I was stepping out into Missionary work with an organisation I had a girlfriend. She wanted me to work first and settle down but I felt I could continue the relationship which was my first real one.
But the Lord gave me a dream which was very vivid - I was in an open white Rolls Royce driving along a highway. My girlfriend was sitting besides me.
Every time we went over a bump she would fly out of the car onto the wayside. I would have to stop, reverse, get out, pick her up and put her back in the car.
This happened many times then the dream stopped.
I was blinded by the situation (wrong relationships tend to do this) and didn't know what it meant. Eventually my friend plucked up the courage to tell me that it meant she was a hindrance to God's pure (white) purposes (car on highway) in my life. Each time we would encounter a difficulty (bump) she would hinder.
I ended the relationship as a result (she took it quite well I must add!)