Connecting to Tisha B'Av A Spiritual Guide

Nobody alive today misses the slaughtering of animals and the blood on the Mizbeach, so how are we meant to mourn the Beis HaMikdash on Tisha B'Av? And why do people read stories of Jewish suffering from other centuries when the day is about the Churban? The Kinos themselves go beyond the destruction, to the Crusades and later. A mashal about an eighteen-year-old who walks out of his parents' house after an argument sets the picture. From there it becomes clear what we actually lost, and how to connect to it.