“Either/Or,” by Elif Batuman (Penguin Press) Do you remember what it felt like to be a college sophomore? The Jell-O shots, cookie dough and moments of abject humiliation and terror as you tried, oh so self-importantly, to figure out how to live? Elif Batuman brings back the tedium and exhilaration of undergraduate life in “Either/Or,” a charming, mordantly funny follow-up to her first novel, “The Idiot,” which was a finalist for the 2018 Pulitzer Prize.