The workshop abutted a warehouse full of table legs – one hundred and sixty-two thousand, three hundred and twenty-nine, so far…  Immediately before taking up woodwork, he’d passionately devoured all the higher mathematics texts in the central library, run all the tutorial software, and then personally contributed several important new results to group theory – untroubled by the fact that none of the Elysian mathamaticians would ever be aware of his work.  Before that, he’d written over three hundred comic operas, with liberettos in Italian, French, and English – and staged most of them, with puppet performers and audience.  Before that, he’d patiently studied the structure and biochemistry of the humen brain for sixty-seven years; towards the end he had fully grasped, to his satisfaction, the nature of the process of consciousness.  Every one of these pursuits had been utterly engrossing, and satisfying, at the time.

“However much you think I’m wasting my time, it’s only for fifty or a hundred years.  What difference does that make, in the long run?”
“You could be more selective.”
“What did you have in mind?  Something socially useful? Famine relief?  Counselling the dying?  Or something intellectually challenging?  Unconvering the fundamental laws of the universe?  I have to admit the TVC rules have slipped my mind; it might take me all of five seconds to look them up again.  Searching for God?  That’s a difficult one: Paul Durham never answers my calls.  Self discovery? – …if I limited the range of options, I’d be repeating myself in no time at all.”

“How does it feel to be seven thousand years old?”
“That depends.”
“On what?”
“On how I want to feel.”

[Permutation City by Greg Egan]

This was the first Greg Egan book i read.  the first science fiction book i ever read which was set (at least in the first few chapters) close to home.  it had a huge affect on me.