It has been said by some that an enlightened being came/happened once every 500 years, but now they seem to be popping up all over the place.
The Buddha had to meditate like hell, he even starved himself to attain it. Monks spend many years doing some are successful some are not.
I think with science looking into these Nirvana states of mind that they will figure out a way to end suffering for the human species which will usher in a whole different way of life with higher intelligence running things.
From my understanding of Enlightenment it is a sort of rewiring of the brain where the signals go up pleasure side of the amygdala where as painful emotions and sensations go up the other side. Negative emotions and pain use up a lot of processing power and so limit true intelligence. An enlightened person has most of his brain signals going up the positive side of the amygdala and so reacts to things that cause pain differently as all suffering has ended he acts with intelligence instead of the painful emotion type reaction.
I feel with the tools we moderns now have we can examine the brain and make the adjustments in the way it processes information so that in the near future we will have a completely transformed species with much more intelligence.
I would even bet that the top governments are looking into this and researching the subject as a real possibility.