from: http://en.wikipedia.org/wiki/Intellectual_giftedness#Depress... "A number of people have noted a higher incidence of existential depression [in the gifted], which is depression due to highly abstract concerns such as the finality of death, the ultimate unimportance of individual people, and the meaning (or lack thereof) of life."
they recognize the irrelevance of everything. it's not uncommon for all types of people to have these sorts of thoughts, but the very abstractive abilities of the gifted mean these are more than just thoughts to them. these issues are as clear, concrete, and tangible as a brick wall is to mere normal humans
compounding things is the fact that these gifted people hold nature in the highest regard, and see it as the only arbiter of truth. they can't escape the irrelevance of everything, because that's just how nature is
it's a painful QED