Example of Lateral Thinking

I went looking for an example of lateral thinking as a follow up on a previous post on this abstract topic. There are millions of posts on the Internet on the subject, but to get a good understanding, quickly, there is nowhere better than Wikipedia.
Anyhow, this example is taken, verbatim, from Wikipedia.

"A man and his son are in a car crash. The man is killed and the son is taken to hospital gravely injured. When he gets there, the surgeon says "I can't operate on this boy- he is my son!" How is this possible?

This is an example of an instant perception blocking the mind's ability to explore alternatives. In this case the instant perception is that most people imagine a surgeon as a male; this leads to the conclusion that either the surgeon or the "father" in the car crash was not the boy's real father.
If you switch your perception to allow for a female surgeon then the answer is suddenly obvious, the surgeon is the boy's mother.
Most people imagine a surgeon as a male, but in this case it is the opposite! Lateral thinking is the method of switching perceptions to allow the alternate view point.
Another example for an instant perception blocking the mind's ability to explore alternatives is that one assumes the surgeon is telling the truth. Maybe he was simply wrong (the son might have looked exactly like his own son) or maybe he was lying, because for some reason he didn't want to operate on him (he could have felt bad or drunk alcohol before).
Or the son could have two fathers - one of them could have been his adoptive father. Or if the boy was one of two separated twins, with the other growing up with the surgeon for whatever reason, then the surgeon would have recognized the boy as his own son.
Or the surgeon is actually talking about the man who died in the accident, making the surgeon the boy's grandfather."

Source:Wikipedia

This gives rise to a better understanding of the concept of "Thinking outside the box" and the classic example of the 9 dots puzzle.
Will do that in the next post.
EDIT : 24 October
While looking up on the Gordian knot I found a debateable example of lateral thinking. When Alexander the Great could not untie the knot, he severed the rope with a single stroke of his sword. He could not solve the problem, but found a solution. More here