The solution depends on what you see unexpected and expected to mean. I define unexpected to mean something that you didn't expect.
Dictionary.com's definitions can be found here and here, and these I agree with.
It is therefore an impossibility to expect the unexpected, because if you expect an event, then it is expected, and other events are therefore unexpected.
Let us say there are two events A and B.
If you expect A to happen, B is unexpected, and A is expected.
If you expect B to happen, then A is unexpected, and B is expected.
Therefore, it is an impossibility to expect the unexpected.
This happens in any amount of events, because expecting an event makes changes it from being unexpected to being expected.
An arguement against this has been posted here although I disagree with it for reasons stated above!