I guess I have finally reached the "old geezer" stage, because I'm starting this post with a "back in the day" leader....
Way back when I started first grade, my grandfather gave me a small, used Imperial peanut-sized pocket knife, saying "Now that you're going to school you need to have your own knife. You can't be borrowing one from other people." Every boy had at least one in his pocket and at least 75% of the girls carried a pocket knife in their purses. I can't remember a day I didn't carry at least one pocket knife, and after I started 5th grade, I carried 2 pocket knives every day. Most of the time they were used to sharpen pencils or play mumbley-peg. Our class room pencil sharpeners seldom worked. And yes, we played mumbley-peg on school property during school hours.

Personally, I still carry a minimum of 4 knives a day - paired folders in the front pockets and paired fixed blades. Redundancy is your friend.
It's only been in the last 8 - 9 years that I have been encountering more men who don't carry at least a pocket knife on a regular basis. Prior to that, I was almost NEVER asked by someone to borrow a knife from me. They had their own. As to how many women carry knives in their purses now-a-days, I don't have a clue. Two things I learned A LONG TIME AGO is "never ask a woman her age and never ask her what she has in her purse".
I have 3 theories -
1 is that I'm encountering more non-native Texans who have moved into the state from knife-unfriendly states.
2 is that people are getting out of the habit of carrying knives due to workplace rules, TSA rules, etc that either ban carrying knives or make it very "socially incorrect"
3 is that both 1 and 2 are jointly contributing to the change.