What dreams may come....

My father died in 1963. I still dream about him. Regularly. My mother died in 1987. I still dream about her. Regularly. I worked for Eurocentres for thirteen years, from 1961 to 1974, I still dream about that time and about the people I worked for. Regularly.
I have no idea why I dream about these things.
I read that if you think, before you fall asleep, about what you would like to dream about, you can influence what you DO dream about. So, why have I not had a dream about Margaret Lockwood in the last thirty years?
Something wrong with the theory there, according to my mind.
One good thing about my dreams, though: I am quite athletic, I do a lot of running and a lot of swimming.
Excuse me, there's someone at the door. I think it might be the doctors from the funny farm......