“The Fantasticks,” a quintessential celebration of love in all its gorgeous simplicity and heartbreaking complexities is opening at Sierra Rep. Beloved by theatergoers for 50 years, “The Fantasticks” is a musical allegory about the romance of a young couple, Matt and Luisa, who find their relationship tested by their meddling fathers and a bandit narrator known as El Gallo. Little do these love-birds know, however, that their fathers are actually good friends who've hatched a plan — with the help of a mystical roving side-show and it’s equally mysterious ring master — to get these two lovers down the aisle! “The Fantasticks” has a classic score by Tom Jones and Harvey Schmidt that includes “Try to Remember” and “Soon its Gonna Rain.”