What is this Universe

Below is excerpts from Sayagyi U Ba Khin's lecture on Buddhism.
Before he starts with the life of Gotama the Buddha he has to explain the universe we live in so he starts with the definition of the Universe. As I paste it below I can't help but wonder how i have spent 40 years on this planet with no knowledge of what comprises the universe I live in.
The complete text from which I have copied the below extract can be found here - http://www.internationalmeditationcentre.org/publications/DhammaTexts.pdf

The Universe 

The Buddhist concept of the universe may be summed up as follows: there is the Okåsa-loka (the universe of space) which accommodates nåma and rupa (mind and matter). In this mundane world, it is nåma and rupa (mind and matter) which predominate under the influence of the law of cause and effect. Next is the Sankhåra-loka (the universe of mental forces), creative or created. This is a mental plane arising out of the creative energies of mind through the medium of bodily actions, words and thoughts. The third and last is the Sattaloka (the universe of sentient beings), visible or invisible, beings that are the products of these mental forces; we may rather call these three the “three-in-one” universe, because each is inseparable from the others. They are, so to speak, interwoven and interpenetrating. 

What will interest you most are the Cakkavålas or worldsystems, each with its thirty-one planes of existence. Each world-system corresponds to the human world with its solar system and other planes of existence. There are millions and millions of such world-systems; they are simply innumerable. The ten thousand world-systems closest to us are within the Jåti-khetta (or the field of origin) of a Buddha. In fact, when the renowned sutta (or discourse), the Mahå-Samaya (meaning the “Great Occasion”) was preached by the Buddha in the Mahåvana (forest) near the town of Kapilavatthu, not only the brahmås and devas of our world-system but of all the ten thousand world-systems were present to listen to the teachings of the Buddha.

The Lord Buddha can also send his thought-waves charged with boundless love and compassion to the sentient beings of a billion such world-systems within the Anå-khetta (the field of influence). The remainder of the world-systems are in the Visaya-khetta (infinite space), beyond the reach of the Buddha’s effective thought waves. You can very well imagine from these concepts of Buddhism the size of the universe as a whole. The material insignificance of our world in the Okåsa-loka (the universe of space) is simply terrifying. The human world, as a whole, must be just a speck in space. 

Now I will give you an idea of the thirty-one planes of existence in our world-system, which, of course, is the same as in any of the other world-systems. Broadly speaking, they are: 

1. Arupa-loka The immaterial worlds of the brahmås
2. Rupa-loka The fine-material worlds of the brahmås
3. Kåma-loka The sensuous worlds of devas, mankind, and lower beings

The Arupa-loka is composed of four brahmå worlds of immaterial state, i.e., without rupa or matter. 

The Rupa-loka is composed of sixteen brahmå worlds of fine-material state. 

The Kåma-loka is composed of: 

(a) Six Deva-lokas (or celestial worlds): 

1. Catumahåråjika (the world of the Four Guardian Kings)
2. Tåvatimsa (the world of the Thirty-three)
3. Yåma 
4. Tusita 
5. Nimmånarati (those who enjoy their own creations)
6. Paranimmita-vasavati (those who enjoy others’ creations)

(b) The Human World 

(c) The four Lower Worlds (apåya): 

1. Niraya (hell)
2. Tiracchåna (the animal world)
3. Peta (the ghost world)
4. Asura (the demon world)

These planes of existence are pure or impure, cool or hot, luminous or dark, light or heavy, pleasant or wretched— according to the character of the mental forces generated by the mind through the volition (cetanå) associated with a series of actions, words, and thoughts. For example, take the case of a religious man who suffuses the whole universe of beings with boundless love and compassion. He must be generating such mental forces as are pure, cooling, luminous, light and pleasant, forces which normally settle down in the brahmå worlds. Let us now take the reverse case of a man who is dissatisfied or angry. As the saying goes, “The face reflects the mind.” The impurity, heat, darkness, heaviness and wretchedness of his mind are immediately reflected in the person—visible even to the naked eye. This is due, I may say, to the generation of the evil mental forces of dosa (anger) which go down to the lower worlds of existence. This is also the case for the mental forces arising out of lobha (greed) or moha (delusion). In the case of meritorious deeds such as devotion, morality, and charity, which have at their base attachment to future well-being, the mental forces generated are such as will normally be located in the sensuous planes of devas (celestial beings) and of mankind. These, ladies and gentlemen, are some of the concepts in Buddhism relevant to the life story of Gotama Buddha.