'A funny thing happend on the way to the forum'

So, I went to the post office today, and had an interesting encounter.

The place was quite full, and in front of me in line was an elderly woman who was struggling with packaging an X-Box for shipping (to her grandkids, if I caught it correctly.) When she got to the counter, the pleasant ( suprisingly so. ) post office clerk advised her to re-open the package, buy a couple of newspapers from out front, and pack it more securely. The Post office worker was fumbling for something to open the box with, and here's where things went weird.

Without thinking about it, I reached into my pocket and fished out my pocketknife. It's a small folder, the blade is -maybe- 2 1/2 inches long. It's a pocket knife in the traditional sense. I opened it, and held it out, resting in the palm of my open hand, handle facing twords the clerk.

She recoiled as if I'd held up a handful of shit. She was startled, and frightened. The grandmother promptly said 'thank you' and snatched it up, and cut the box open, and then handed it back to me.

I blinked a couple of times, and looked at the clerk. I smiled tentatively and said 'Ma'am, it's a pocket knife, not a rattlesnake.' The crowd laughed, I smiled at her, the clerk smiled back I put the tool back in my pocket.

But what gets me is this.

At what point did we as a culture start looking at flippin pocket knives as weapons?