Our galaxy, the "Milky Way" would take 200,000 years to cross -- traveling at the speed of light. It is known to contain about 200 Billion stars. Approximately 125 Billion galaxies are presently known to Science... that adds-up to about 25 Sextillion stars (25 followed by 21 zeros).
The inner workings of the human brain is the make-up of what we call "human nature". Amazingly, it has been calculated that the number of permutations (of possible connections between the synapses within a single mind) gives rise to a larger number.
"We are starstuff", "We are one species", "History is full of people who out of fear, or ignorance, or lust for power have destroyed knowledge of immeasurable value which truly belongs to all of us. We must not let it happen again." - Dr. Carl Sagan
In his Memory.