Each book needs a good beginning and a good ending. People get pissed off when you don't close things off properly at the end.
Patrick RothfussThe key to good worldbuilding is leaving out most of what you create. You, as the author, had damn well better know the where all that dragon food comes from, but that doesn't mean that I, as a reader, want to read a five thousand word essay about you explaining it to me. I don't need to see the math, but I can tell by the details you provide whether or not you've thought these things through to their logical conclusions.
Patrick RothfussYou're sure your new roommate won't be like the last one who wore tinfoil socks and had a tendency to occasionally urinate in the refrigerator. You're sure you'll pass Math 106 this time around. You're determined to actually join some clubs this year and not just sit around in your dorm eating spray cheese from a can and watching youtube videos about cats.
Patrick RothfussAfter an awkward pause, Bast extended his hand. Chronicler hesitated for a bare moment before reaching out quickly, as if he were sticking his hand into a fire. Nothing happened, both of them seemed moderately surprised. "Amazing, isn't it?" Kvothe addressed them bitingly. "Five fingers and flesh with blood beneath. One could almost believe that on the other end of that hand lay a person of some sort.
Patrick Rothfuss