I have been paxing for 42 years (avg amount, I suppose) and never had an RTO or go round, on any a/c ever. I am REALLY disappointed about this and need to add them to my list of war stories.
Recall watching my grandmother's departure from JNB enroute LHR in about 1970. The VC-10 was moving smartly down the runway when it stopped and then simply trundled back to the start, via the taxiway. Short wait to check out whatever it was that appeared to be wrong (lots of staff on the flight deck to make the checks!!!) and then departed as normal.
In an exchange of letters, my mother asked if they had said what was wrong, my grandmother (who must have been 65) replied, "I thought that they always did a trial run."