I quizzed him a lot on this point and i suspect the truth was that it was like a lot of things at that age: you don't have any clear reason, you just do it. You do it because you think it might get a laugh, or because you want to see if it'll cause a stir. And when you're asked to explain afterwards, it doesn't seem to make any sense.
Kazuo IshiguroBut then, I suppose, when with the benefit of hindsight one begins to search one's past for such 'turning points', one is apt to start seeing them everywhere.
Kazuo Ishiguro