What has to do with your ability to fall asleep is not caffeine. It's having a clean conscience. I have a clean conscience so I can drink all the caffeine I want.

Dreams are associated with a state called REM sleep, the abbreviation standing for rapid eye movement. The REM state is strongly correlated with sexual arousal. Experiments have been performed in which sleeping subjects are awakened whenever REM state emerges, while members of a control group are awakened just as often each night but not when they're dreaming. After some days, the control group is a little groggy, but the experimental group - the ones who are prevented from dreaming - is hallucinating in daytime. It's not that a few people with a particular abnormality can be made to hallucinate in this way; anyone is capable of hallucinations.

caffeine nap”: Drink a cup of coffee or tea, lie down for fifteen minutes, and get back to work when the caffeine has kicked in.

Dream girl, please do not wake me so I may continue to dream...

A still greater control is exerted over the thoughts during seep by their character during hours of wakefulness. By controlling the mind during entire consciousness, it will also be controlled during unconsciousness or semi-consciousness. Dr. Acton makes the following very appropriate remarks of this subject:- “Patients will tell you that they ‘’cannot’’ control their dreams. This is not true. Those who have studied the connection between thoughts during waking hours and dreams during sleep know that they are loosely connected. The “character” is the same sleeping or waking. It is not surprising that, if a man has allowed his thoughts during the day to rest upon libidinous subjects, he should find his mind at night full of lascivious dreams--the one is a consequence of the other, and the nocturnal pollution is natural consequence, particularly when diurnal indulgence has produced an irritability of the generative organs. A will which in our waking hours we have not exercised in repressing sexual desires, will not, when we fall asleep, preserve us from carrying the sleeping echo of our waking thought father then we dared to do in the day-time.”

There is some evidence that dreaming is necessary. When people or other mammals are deprived of REM sleep (by awakening them as soon as the characteristic REM and EEG dream patterns emerge), the number of initiations of the dream state per night goes up, and, in severe cases, daytime hallucinations-that is, waking dreams-occur.

drinking caffeine is a way of borrowing energy from later on in the day.

But when you can’t sleep at night, how can you dream?

Much more plausible is the computer-based explanation that dreams are a spillover from the unconscious processing of the day's experience, from the brain's decision on how much of the daily events temporarily stored in a kind of buffer to emplace in long-term memory... The American psychiatrist Ernest Hartmann of Tufts University has provided
anecdotal but reasonably persuasive evidence that people who are engaged in intellectual activities during the day, especially unfamiliar intellectual activities, require more sleep at night, while, by and large, those engaged in mainly repetitive and intellectually unchallenging tasks are able to do with much less sleep.

If you want to improve your understanding, drink coffee.

Some dreams are best not to wake up from.

Life-hack: When in bed, meditate. Either you will have a deep meditation or fall asleep. Victory either way.

Meditate in bed. Either you will fall asleep or have a deep meditation. Victory either way.

There is a kind of sleep that steals upon us sometimes, which, while it holds the body prisoner, does not free the mind from a sense of things about it, and enable it to ramble at its pleasure. So far as an overpowering heaviness, a prostration of strength, and an utter inability to control our thoughts or power of motion, can be called sleep, this is it; and yet we have a consciousness of all that is going on about us; and if we dream at such a time, words which are really spoken, or sounds which really exist at the moment, accommodate themselves with surprising readiness to our visions, until reality and imagination become so strangely blended that it is afterwards almost a matter of impossibilty to separate the two. Nor is this, the most striking phenomenon, incidental to such a state. It is an undoubted fact, that although our senses of touch and sight be for the time dead, yet our sleeping thoughts, and the visionary scenes that pass before us, will be influenced, and materially influenced, by the mere silent presence of some external object: which may not have been near us when we closed our eyes: and of whose vicinity we have had no waking consciousness.