ok let me explain..

i was driving around. checking the economy of my car by driving 100K's and back and when i reached the petrol station to fill up, i cut the ignition and the went to pay for the fuel.. however, when i went to start the car again, it wouldn't turn over. in fact, nothing would turn over at all.. when i opened the door after paying the light was still working. i pushed the car into the nearest parking space available and sat there for about 5 mins, making sure everything was switched off (interior light was set to off, radio was completely off). Then i tried again thinking "great, i'm going to have to call roadside assist) and then it started.

Is my ignition coil on the way out or is it something else entirely electrical? Any ideas at all?

P.S. Battery was fine and was well and truly charged after the drive.