For quite some time since I was old enough to I went everywhere with my pocket knife. Let’s say it was between 1973 and 2000 or so.
One single, very conscious and grudging exception: the years when having any such object in your pocket in my home town could get you in some security trouble. Those days, I still carried it around when traveling.
In 2000 or so I happened to forget leaving it home when taking a plane, and risked having to waste it. To prevent further such risk, I left it home ever since.
Thinking of that, this vastly overestimated the scant chance I might need to board a flight unplanned the same day.
Last week, as I was talking about hiking with friends, I just realised my odds of needing to use a pocket knife at any given time are much better than those of needing to board a plane, as they probably have always been.
My pocket knife is back in my pocket or backpack, alongside selected daily essentials. I will try to remember taking it out when preparing for air travel.