Paul Potts is a good pop singer who happens to sing opera; no detraction there. I prefer Placido Domingo (youtube should have dozens of versions of Nessun Dorma) But I will suggest something else. Perhaps it is the music which we find so moving.
There is a legendary study of "opera rhapsody," which effects some people who have reproducible rapture on hearing certain operatic selections. It turns out that opera rhapsody, like "runner's high," can be blocked naloxone, a blocker of the endorphins (endogenous brain narcotics). So certain music can overwhelm the nervous system with...feeling.
OK. Opera is not weightlifting, but there is something about the pursuit of quality, the appreciation of excellence, which they share. So now that you have heard it sung well, imagine what it feels like when sung excellently.