On my QXC for my PPL, I was assigned for a flight to Staverton and back to Peterborough, via Bourne.
The flight itself went very well - I arrived into Staverton on time, and with a big smile on my face. Uploaded fuel, had a coffee, and then started redoing my checks. No problems there, taxied out to the hold. Announced that I was ready for departure... and then without reason, continued to taxi. Onto the runway. Right in front of an arriving PA28.
To say that the pilot of the PA28, the ATC and the flying club back in Peterborough were not best pleased is an understatement. I couldn't think of a suitable reply to Staverton Tower either, so I just said something really stupid. I can't rememeber what it was though...
If I ever meet the pilot of that PA28, I owe him a beer. I'm so sorry about that to this day. I learnt flying/taxying from that!!!