I go in huge lapses of having them fairly regularly (like 1/week) to not even being able to recall my dreams at all. I feel that the amount of sleep you get is a huge factor. If you wake up to an alarm, your mind is instantly diverted to the waking world. But if you take the few precious seconds when you wake up to recall what you were just dreaming about, it becomes a big difference maker in recall and eventually lucids.