DM says: «There's one issue. The wizard's tower is warded against scrying and teleportation.»
DM means: «OH IT LOOKS LIKE THE BOOT OF ELVENKIND'S ON THE OTHER FOOT NOW MR WIZARD.»

DM says: «You see an empty hallway.»
DM means: «DC 30 Search for traps, DC 25 to disable, complex skill check, 5 successes before 3 failures. Oh, and the water flooding may cause a lapse in concentration, so it comes out to...»

DM says: «So, tell me your character's background history.»
DM means: «So, tell me how I'm going to get you into the party and plot.»
Players hear: «So, tell me a good long story about your character's childhood.»