Took me about 1 1/2 hours to fit a new throttle cable on the 172, it snapped whilst my other half was out in the car and left her and the kids stranded on a dual carriageway - nice AA man only took 1 hour to come out and cobble together a temorary fix to get her home.
I would blame it on her lead foot, but I have to admit I did notice it was a tad frayed down by the pedal when we bought the car so my fault really, should have fixed it earlier. Anyway I am now an expert on the tourturous procedure for replacing the cable if anyone else is unlucky enough to break one and feels brave enough to fix it themselves!