By Peter Gould
BBC News, Rome
The disclosure that John Paul II contemplated resignation comes as a surprise.
The Pope's health problems may have tempted him to quit
Despite his long illness, he always gave the impression that the papacy was a mission given to him by God, and only God could decide when it should come to an end.
But the fact that he considered standing down in the millennium year of 2000 is significant.
It was around this time that Parkinson's disease really started to have an impact on his physical health.
It was also the year in which he reached the age of 80, and according to the rules for electing a Pope - rules he endorsed - only cardinals under that age are allowed to vote.
When the cardinals meet to choose a new Pope, many will be asking themselves about the age and health of the likely cardinals
It raised the question of whether, if you were too old to vote for a Pope, you were also too old to be Pope.
So there was speculation that John Paul II might use his birthday in 2000 as an appropriate date to stand down in favour of a younger and healthier man.
But there must have been doubts in the Pope's mind about the wisdom of such a move.
It is hundreds of years since a Pope resigned. The tradition is that the pontiff remains in office until the day he dies.
The concern is whether the Church could cope with two living popes, one in retirement and the other in the Vatican.
In any event, John Paul II clearly decided it would best to carry on, despite his growing infirmity.
In the weeks before his death, however, questions were asked about the extent to which he was really in control of events in the Vatican.
The suspicion was that the Vatican was increasingly being run by a small group of trusted advisors, who knew the Pope's mind, and were able to take many decisions.
But despite the death of John Paul II, the resignation issue has not gone away.
When the cardinals meet to choose a new Pope, many will be asking themselves about the age and health of the likely cardinals.
They will not want to elect someone so old that he has difficulty in doing the job.
But they may not want to elect a younger man who could remain in office for many years, perhaps even longer than John Paul II.
However, they might find their decision easier if there was an understanding that the Pope should retire at a certain age, or stand down earlier if he becomes ill.
As the papacy of John Paul II neared its end, his aides said that resignation was purely a matter for him.
Some cardinals may now be thinking that it is an issue that should be discussed before the conclave.