You my friend sound like me, but it takes amanda scratching at my back to wake me... Anyways the reason it last's longer if you leave it on is because the parts dont have to "contract" because of them cooling back down.... Heat = Expansion, Cold = Contraction, you keep turning it on and off and it keeps expanding and contracting causing damage over time, and when you do leave it on at night if not doing anything, it will just sit there and Idle and stay at a decent temp.... and them wires will not catch on fire.... Takes very high temps or a lot of shortage to catch them on fire....