The rigour of the purifying flames is so great that one moment of their endurance is more pain-inflicting than many years of severe penance in this world. What, then, must not those poor souls have undergone who have spent the longest time in that place of torture? Let us try today to alleviate their sufferings and abridge their exile.
We all expect, doubtless, or think ourselves sure, to go to Purgatory. If we do not think much of the matter at all, then we may have some vague notion of going straight to Heaven as soon as we are judged. But if we seriously reflect upon it - upon our own lives, upon God’s sanctity, upon what we read in books of devotion and the lives of the Saints - I can hardly conceive anyone of us expecting to escape Purgatory, and not, rather, feeling that is must be almost a stretch of the Divine Mercy which will get us even there. Now, if we really expect that our road to Heaven will be through the punishments of Purgatory - for surely its purification is penal - it very much concerns us to know the views of this state that appear to prevail in the Church. These views agree that the pains are extremely severe, as well because of the office which God intends them to fulfil, as because of the disembodied soul being the subject of them. They agree, also, with regard to the length of the suffering. This requires to be dwelt upon, as it is hard to convince people of it, and a great deal comes of the conviction, both to ourselves and others.
The duration may be understood in two ways: 1. as of actual length of time; and, 2. as of seeming length from the excess of pain. With regard to the first, …we shall find among some hundreds of cases that by far the greater majority suffered thirty , forty  or sixty  years. Here are some of the examples: A holy Bishop, for some negligence in his office, had been in Purgatory fifty-nine years , before he appeared to the servant of God i.e. Sr. Francesca of Pampeluna; another Bishop, so generous of his revenues that he was named ‘the almsgiver,’ had been there five  years because he had wished for the dignity; a priest forty  years because through his negligence some sick persons had died without the Sacraments; another forty-five  for inconsiderateness in his ministerial functions; a gentleman forty-nine  years for worldliness; another sixty-four  for fondness for playing at cards for money; another thirty-five  years for worldliness.
Without multiplying instances, which it would be easy to do, these disclosures may teach us greater watchfulness over ourselves, and more unwearied perseverance in praying for the departed. We see that our charitable attentions towards them must be far more vigorous and persevering than they have been; for that people go to Purgatory for very little matters, and remain there an unexpectedly long time. Their most touching appeal to us lies in their helplessness; and our dear Lord, with His usual loving arrangement, has made the extent of our power to help them more than commensurate with their inability to help themselves. We can make over to them, by way of suffrage, the indulgences we gain, provided the church has made them applicable to the dead. We can limit and direct upon them the intention of the Adorable Sacrifice. We can give to them all the satisfactions of our ordinary actions and of our sufferings, and in many other ways we can help the suffering souls.
It is related of a religious of St. Dominic that, finding himself at the point of death, he earnestly begged a friend who was a priest to have the goodness, as soon as he was dead, to offer the Holy Sacrifice of the Mass for the repose of his soul. He had scarcely expired when the priest went to the church and celebrated Mass with devotion for this intention. The Holy Sacrifice being over, he had scarcely taken off the sacred vestments when the deceased religious presented himself to him and rebuked him severely for his hardness of heart in leaving him in the most cruel fire of Purgatory for the long space of thirty  years. ’ How thirty  years?’ asked the good priest, in amazement. ‘Why, it is not yet an hour since you departed this life, so that your corpse is, so to say, still warm.’ To this the poor soul replied: ‘Learn hence, my friend, how tormenting is the fire of Purgatory when scarcely an hour seems to be thirty  years, and learn, too, to have pity on us.’
Taken from Thirty Days’ Devotion to The Holy Souls ~ ‘Forget Me Nots from Many Gardens’