This playgoer's memory of A. R. Gurney's Love Letters -- the 1988 two-character play consisting of letters between an upper crust boy-turned-man and girl-turned-woman, performed without memorization or blocking by a middle-aged pair of star actors -- is of an amusingly entertaining but slight affair.
Even the people who've had experience with addiction, molestation, abusive fathers, hysterical mothers, horrible politicians, and Russian sporting events are not necessarily experts. At least not in the classic sense. They can be experts about themselves, their experiences. But no one else, no one else's experiences.