"The Biblical view of things is resurrection -- not a future that is just a consolation for the life we never had but a restoration of the life you always wanted. This means that every horrible thing that ever happened will not only be undone and repaired but will in some way make the eventual glory and joy even greater." (The Reason for God, pg. 32)
To state it another way, he quotes C.S. Lewis:
"They say of some temporal suffering, 'No future bliss can make up for it,' not knowing that Heaven, once attained, will work backwards and turn even that agony into a glory." (from Lewis' book The Great Divorce)
This isn't just something we learn from Keller and Lewis though. The Apostle Paul tells us the same thing:
So we do not lose heart. Though our outer self is wasting away, our inner self is being renewed day by day. For this light momentary affliction is preparing for us an eternal weight of glory beyond all comparison, (2 Corinthians 4:16-17 ESV)
Look forward with hope today not because you'll one day be able to forget about this current moment but rather because you'll look back on today gloriously as the future works backwards into it.