LOS ANGELES, April 15 (UPI) -- Season 2 of The Rehearsal , premiering Sunday on HBO, takes Nathan Fielder's social experiment to exponentially deeper levels. The extent of his study makes the season absurdly funny, yet the conclusions he comes to are poignant. In Season 1, Fielder hired actors and built sets to allow real-life people to practice difficult confrontations. The sight of people practicing on doubles played by professional actors was funny, but it did sometimes help them. Fielder