A common challenge for your ~ancestor~ ancestors likely revolved around their tendency for extreme idealism. Those having unrealistic or utopian ideals would have found life difficult (for them and those close to them). Some may have become depressed due to their inability to be satisfied with what they had achieved or the material reward they felt was owed them. 

Those who overcame this challenge likely did so because they recognized the many reasons, they had to be grateful, and were able to find a balance between their ideals and more practical notions. 