The list above is based on a careful analysis of thousands of dream reports collected prospectively (for example, on daily dream logs) as opposed to asking people about the last nightmare they remember on a questionnaire. Themes of falling or being paralyzed appear infrequently in dream logs, but their high saliency makes them particularly memorable and thus more likely to be recalled in interviews or questionnaires long after their occurrence and many people can remember having one of these nightmares at least once in their lifetime, often many years ago. So nightmares of falling or being paralysed are certainly common in the sense that many people remembering having had such a nightmare at least once in their lifetime, but the themes above occur much more frequently over any given week, month, or year.
Also, it is important to bear in mind that themes of falling, being paralyzed, or suffocation may well represent other commonly experienced parasomnias such as hypnic jerks, isolated sleep paralysis, or sleep terrors. When faced with broadly defined questionnaire items, people may be more likely to report these types of sleep experiences as if they were nightmares. Providing subjects with clear definitions for nightmares as well as sleep terrors and requiring actual dream narratives to be reported in daily logs greatly reduces the inclusion of other sleep phenomena in these results.