Just quoting, from Larry Niven, Jerry Pournelle, Dean Ing and S.M. Stirling 's Man Kzin Wars 2:
"How would it be to know that you were a made thing, and doomed to encysted madness in six months or less? Nobody had ever been able to learn why. He had speculated to himself that it was a matter of time; to a consciousness that could think in nanoseconds, that could govern its own sensory input, what would be the point of remaining linked to a refractory cosmos? It could make its own universe, and have it last forever in a few milliseconds. Perhaps that was why humans who linked directly to a computer system of any size went irretrievably catatonic as well...."