Edited for the WHOLE truth.
I remember learning in a catechism class (pre-council)that purgatory likely was experienced in either or,and sometimes both,the temporal and supernatural worlds. The instructor said that a Just God would not reward two people,one who always successfully resisted temptation and one who fell often but repented,confessed and was forgiven,in the same manner. Cleansing or purging is/was required for the many sins committed,even though forgiven,to assure perfect justice was effected.
I recall hearing that many people who had suffered so very much in WWII probably had served their purgatory and upon death went to God. I always found that comforting.
Perhaps,if you and I go directly to heaven,we will be grateful for Weakland and O'Brien's reigns.