As befits a blog named after a club for gentlemen’s personal gentlemen, all the wisdom here is in the comments.

From the Parable of Fertile Soil:

Hell is meeting the person you could have become.

-thus Rozy

Books pointed out the quip could be taken in two ways:

1) the bad person you could have become without the gospel.
2) the superlative person you could have become had you fully lived up to your potential.

There is a long tradition of quips about hell, and long may it continue.  But to my mind, these are more than quips.  They are probably pretty close to the actual reality of hell.  Hell for the wicked is knowing exactly who you are and exactly who you could have been.  Hell is the horror of knowing people better than yourself, knowing you could have been them, and the horror of knowing people like yourself, hating them and yourself also.  Whether it is hell or purgatory depends, of course, on what you do with this knowledge.

We can taste hell now.  I most truly feel the weight of my sins when I most truly feel what God meant me for.  And from time to time I run across someone who has made a wreck of themselves and discover how similar we are, how but for one or two small graces or almost accidental little choices I would be in the same boat as they are.  In other words, how dangerous and fundamentally broken my less-than-saintliness is.

I believe this is what hell means because it has the same beauty and feeling of rightness that leads physicists and mathematicians to know they are the right track.  If there is some kind of actual punishment in hell (or spirit prison or outer darkness) it is meant as a mercy and a chance for redemption.  Lewis had something in the same idea in Pilgrim’s Regress.