The element of surprise

"What the hell, he thought, you're only young once, and threw himself out of the window. That would at least keep the element of surprise on his side."
-Douglas Adams

Although jumping out of a building is perhaps not the best use of the element of surprise, is not the easiest way to gain an advantage by doing something unexpected? Every time you do something different, a little odd per se, you can not help but gain some advantage because whoever or whatever you're dealing with is forced to rethink the situation. Putting something in a new light is never a bad thing.

Consider the following (well known) problem:

A convict heard the judge's veredict:
"for your crimes, you shall be executed one day of the coming week. You can not know which day you shall be executed until noon of that same day"

in short we have

1. a convict shall be executed in one of the next 7 days (he know this)
2. he must not know which day he shall be executed until that day arrives

The convict upon hearing the sentence placed the following argument:

I know then that I shall not be executed on the seventh day, for if I were alive I would know that I would have to be executed on that day (thus failing II).

We have eliminated day 7 as a possible execution date so we have 6 days remaining for it.

If the morning of the sixth day comes, I would know that I would have to be executed that day (since number 7 has already been eliminated) and, for II) to be true , I cannot be executed on the sixth day.

I can make the same argument for days 5, 4, 3, 2, 1, and as such I can never be executed based on that sentence for it would violate II). But if I'm not executed, it'll violate I).

The judge didn't listen, and the convict was executed in the afternoon of day 4. Both I) and II) were true.

This is the element of surprise.