There was no way she could know, but Prisoner Zero asked anyway because he was talking to himself; which was all anyone ever did, it seemed to him, t… - Jon Courtenay Grimwood

The thought came and went, more wish than thought. Maria wasn’t good at considering her own emotions. Most of the time the girl found it hard to believe that what she felt might matter.

Immortality had been perfected, at least in its non-biological forms, but insufficient attention had been paid to the boredom of eternity and the corrosive nature of the ratchet effect which demanded ever sharper, stronger and more intense sensations to maintain something like the same level of satisfaction.
Living forever turned out to be much like long-term sex, psychologically tricky; which was why what killed the original colonists was not hardship but boredom.

Why would we do this? she asked, watching smoke trickle towards the ceiling. A whole world of rigid rules covering temperature, convection and Brownian motion all busily pretending to be truly chaotic.