It is amazing how many people still say, "I never dream," for it is now decades since it w

as established that everyone has over a thousand dreams a year, however few of these nocturnal (夜间发生的) productions are remembered on waking. Even the most confirmed "non-dreamers" will remember dreams if woken up systematically during the rapid eye movement (REM) periods.

These are periods of light sleep during which the eyeballs move rapidly .back and forth under the closed lids and the brain becomes highly activated, which happens three or four times every night of normal sleep.

It is a very interesting question why some people remember dreams regularly while others remember hardly any at all under normal conditions. In considering this, it is important to bear in mind that the dream tends to be an elusive phenomenon for all of us. We normally never recall a dream unless we awaken directly from it, and even then it has a tendency to fade quickly into oblivion.

Given this general elusiveness of dreams, the basic factor that seems to determine whether a person remembers them or not is the same as that which determines all other memory, namely degree of interest. Dream researchers have made a broad classification of people into "recallers"—those who re member at least one dream a month—and "non-recallers", who remember fewer than this. Tests have shown that cool analytical people with a very rational approach to their feelings tend to recall fewer dreams than those whose attitude to life is open and flexible. It is not surprising to discover that in Western society, women normally recall more dreams than men, since women are traditionally allowed an instinctive, feeling approach to life.

In modern urban-industrial culture, feeling and dreams tend to be treated as frivolities (无聊事) which must be firmly subordinated to the realities of life. We pay lip-service to the inner life of imagination as it expresses itself in the arts, but in practice relegate (置于次要地位) music, poetry, drama and painting to the level of spare-time activities, valued mainly for the extent to which they refresh us for a return to work.

Many people are unaware that they dream because ______.

A．their dreams fade very quickly

B．they do not recall their dreams

C．they sleep too heavily

D．they wake up frequently