The original code (which we have) has a LAST_JOKE define which is equal to 42. The toldJoke array is a bit larger, because
[toldJoke (+ 3 LAST_JOKE)] ;** a little extra never hurts
The code will try 1000 times to tell all the jokes (I don't care to calculate the probability of that happening), and it it can't, it jumps straight to the duck sequence. If we succeed before that, of course it doesn't take 1000 jokes.