No one living would know how Purgatory feels, because you have to die to go through it.
Purgatory is the purgation of our souls from the effects of sin. Therefore, it is a kind of healing, and at the same time a cleansing or purification. I would imagine that much like babies who are put into a tub when they don't want to, Purgatory can be uncomfortable and not exactly what was hoped for however it is necessary and unavoidable because nothing unclean enters Heaven (cf. Revelation 21:27). In more medieval times it was regarded more as a punishment, but that is not typically a modern view, which emphasizes the purification.
A good scriptural basis for it can be found in St. Paul's letter to the Corinthians:
11 For no other foundation can any one lay than that which is laid, which is Jesus Christ. 12 Now if any one builds on the foundation with gold, silver, precious stones, wood, hay, straw — 13 each man's work will become manifest; for the Day will disclose it, because it will be revealed with fire, and the fire will test what sort of work each one has done. 14 If the work which any man has built on the foundation survives, he will receive a reward. 15 If any man's work is burned up, he will suffer loss, though he himself will be saved, but only as through fire.
1 Corinthians 3:11-15
The image is passage through fire, burning away that which is not wholesome or unworthy. All of our doings are measured, and the good we do will stand on the day, which signifies judgment.
Ultimately, Catholic life is affected by Purgatory inasmuch as it provides an incentive to live a life that is full of goodness, that merits reward, and not unworthiness which provides damage to one soul and also potential harm to others.