Slam

– There you go. What did I tell you?
– What did you tell me?
– Andy Murray. Winning Wimbledon.
– Yes. Of course. A wonderful achievement... What did you tell me about it?
– Didn't I say he would win?
– When was this?
– Oh, ages ago. Didn't I?
– I'm not sure...
– Straight sets. 6-4; 7-5; 6-4.
– Did you give that much detail? I think I would have remembered. It doesn't ring any bells.
– I don't understand how you can have forgotten.
– Did you write it down anywhere?
– Write what down?
– Your prediction. If you had written it down, and dated it, in the presence of witnesses, it would have helped.
– Would it?
– And placed it somewhere safe. A bank vault, say.
– You're not very trusting. Perhaps I just have a talent for these things.
– Predicting major sporting events?
– Yes. The only downside is I only manage to get it right once every 77 years.