Obstacles that we face in life have a tendency to relly get our attention, and tax our knowledge,and wisdom to overcome them. When we're faced with problems we have to figure out solutions. No problems,, no need for solutions.
Evolution, the survival of the fittest, or perhaps sometimes survival of the smartest,, this has to be the force behind the development of the greater human brain apart from other animals. As our ancestors evolved,, the dumber ones,, had fewer opportunities for sex(procreation),, perhaps through not being smart enough,, or not living long enough.
That's why I think, that an idyllic paradise would breed dummies. If everything were pain free, and trouble-free,, consciousness of the human race would atrophy,, because conflict would be absent,, with all our needs met there would be no need to struggle.
If there was no evil there would be no good,,these two opposites need to the exist to define the other. Without no evil there would be no good without Evil there would be no struggle without evil Consciousness would atrophy in human race.