Today, I watched the TED video "Chip Conley: Measuring what makes life worthwhile".
In the video, the speaker quoted an Abe Maslow saying:
If the only tool you have is a hammer, everything starts to look like a nail.
After that, he says, "We've been fooled by our tool." In the next scene, he says, "Excuse that expression," and audience laugh.
I cannot understand why they laughed then.